Mother of god this achive is hard. Harder than Deathwish. Most of the difficultiy comes from he fact no one has any skills. So no Inspire, Transporter, Fast Hands, etc.
The weapons you're stuck with aren't actually that bad.
Also suits, with no skills. You get minced by everything.

Anyway here's the trick: 2 people, 2 bots. The bots will act as meat shields and as a easy way to get extra ammo. I've heard people say 3:1 is the magic number, but I prefer 2:2 because each person can have a bot.

Set-up
Make sure you have no skills on and a usefull perk deck set. Personally I went rogue, but Armourer would work too. The lobby should be set to private to avoid any drop-ins and also make sure your connection won't cut out or lag.

Day One

Outside
There are alot of weak cops scattered around and they hurt.
Snipers will spawn in set spots so be ready to shoot them as they pop up.
There is an "ideal" route but basically you should be trying to stay ahead of the van while taking cover behind the cars.
The best case senario is that you don't get a SWAT van blocking the road. It's passable but a massive pain.
After you give the van the signal on the final turn, run behind the ticket box. It'll give you more than enough cover while the car makes it to the gate.

SWAT Van Turrets
They can spawn on any of the static SWAT vans (not the ones you drill) and make things more difficult. If you use the cars as cover and stay out of the line of fire, you'll be ok. The bots have a nasty habit of standing right infront of it, but that just takes the aggro. It's basically a big, inmobile Skulldozer. So use cover and just run away, since they can't follow you inside. The bots will die, but they aren't too vital for day 1.

Inside
As soon as those doors open run to the first door you can see. Have one person pick and the other cover, even though the wave is over, cops will spawn out of the lifts. If you're lucky you'll find the right door quickly, if not just keep who ever is picking well covered.
Just be ready when you find the right door, you'll have a black dozer to deal with. All you have to do is unload your gun on his faceplate. If you're lucky you'll make it out ok.
After he's dead, start the timer and defend. After it's done drop the bollards and sprint to the car. Signal the driver and run to the escape area. Cops will spawn from the open door and the lifts so be ready. Remove the armour and use the ticket and day 1 is done.

Day Two

Those agents hurt like mother huggers. Basically your goal is to find the keycards as soon as you can. If you want to can dupe cards but it works fine with the basic 4. I was lucky both times I did this and only got 2-3 doors. With the 4 cards, we closed 2 doors got infirmary and saved the last for the final door.
How you tackle this day depends on where the doors and power box are.
Two snipers will consantly spawn on the side with the skywalks, so if there are any doors on that side, close them. If there's a door near the power box, shut it too. Each box spawn has it's advantages and dissadvantages but there's not real bad spawn. Basically you need to make sure you don't get overrun in the operations room, since you have to spend most of your time there.
Everyone has their likes and disslikes for the 3 things you have to bring to Hoxton, personally the best are Forensics and Archives. The rest have they're good and bad points, since you have no skills, moving the server back from IT is a pain for example.

After all that you have to get the server out and survive the final assualt.
Whoever has the keycard should run ahead and open the door up. Whoever is left should grab the server. You can either walk the server down the stairs or just throw it off the balcony and run down.
Just do it fast and be out before too many bulldozers spawn.

Tips and Tricks

• Make sure the lobby is set to private, any drop-ins will void the attempt.
  
• You can use any melee weapon.
  
• You can use any weapon mods.
  
• You don't have to do it on pro, since you will need to do alot of restarts.
  
• Save grenades for when there are alot of shields or bulldozers around, they're good for clearing doorways.
  
• On day 1 it's not vital to kill everything, just run to the next point of cover.
  
• This achive is very hard to get, don't be disheartened if you keep failing. I know some V-100s who can't do it.
  
• Stick together and comunicate, you need to be able to move quickly and carefully.
  
• Team up with someone you know you work well with.
  
• Learn the map, if you haven't done HB alot, play the map a few times so you know where everything is.
  
• The car store on day 1 looks like it's a good spot to go for cover, it's not. It's very open and right next to a spawn.
  
• The cars that line the road, on day 1, are your best bet for cover.
  
• Watch for snipers, they will take a massive chunk out of your health.
  
• Let the bots get focused, it's means the cops aren't focusing you.
  
• SWAT van turrets are static, they can't chase you or hit you if you're in cover.

And that's it.

It sounds alot more simple than it is.
This has got to be one of the hardest achives in Payday 2.
Basically this is more about luck and skill, so before you just comment that "it didn't work" remember I am over 8-65 with 600+ hours played and this is how I did it.
Personally I found this way harder than Deathwish, because DW doesn't limit you to a certain loadout. Also I wouldn't be suprised if the majority of people can't get it. Not only is it hard, it requires perfect teamwork, it can be done solo but it's a big ask. I have seen people solo it but a poor team-mate is a massive thorn in your side for this.
Here's the video, me and Ax had alot of fun doing this at 5am:
Note we did this right after side jobs came out but before SWAT Van Turrets, so keep that in mind. So there's no turrets but I mentioned before about them being more bark than bite.

Anyway, any comments/feedback are more than welcome.

FAQ
Either via the comments or by PM I've been asked various questions, so I'll add them here.

Q: Should I open Armour or Infirmary Day 2?
A: Personally I didn't need either, but if you need to and have the cards go for it.

Q: I have the armour bag, does that mean I can bring armour and put it on later?
A: NO NO NO NO NO. Read what the achivement says. Even with the bag, it'll still void the attempt.

Q: Should I open it up to pubs for the other spot/spots?
A: If the magical fairies in your world think so. But if you live in reality, then NO. I've had my share of both good and bad pubs, but I still would just leave the extra spots open and set the lobby to private.

Q: Do I need 4 human players?
Read the guide and the achivement. Any achive the requires 4 people will say "you and your 4 man crew" in the description.

Q: The bots are standing infront of me and blocking my shots, what should I do?
A: I'm not sure if it's a bug or a feature but you can't shoot through bots like you can do players. personally I just used them as cover while I was reloading or moving something. If it's kinda annoying, just keep calling them and they'll move.

Q: I know you said rogue or armourer for the perk deck, but what about the others?
A: Those two are my personal preferences, by all means try the others, but they're the two I found the most usefull. People are suggesting burgler now, for the doors day 1, but I still like armourer and rogue.

Q: Do you need to use voice chat?
A: Personally I did, it made it easier to coordinate who was doing what. Still I know many people who are perfectly fine just using text, even in DW.

Q: Hey you did the achivement, can you help me do it?
A: Sorry but no. My internet is patchy to say the least and I get epic lag even with people in the same area as me. The best thing you can do is head to the Crews and Clans section of the Steam forums.

Q: What do you have against pubs?
A: I have nothing against pubs. Cheaters, trolls and all-round poor players are what I have a problem with. Nothing is worse than going for an achivement like this only for some ♥♥♥♥ to ruin it.
If you want to go for achivements, do them with a pre-built team, it'll save you alot of time and rage.

Q: What level do the weapons unlock at?
The Golden AK unlocks at 17 and the Typewritter at 14. You might want to get a few more levels so you can get a better melee weapon tho.

Q: The turrets keep killing me, what can I do?
Ignore them. Sure they do alot of damage, but they can't chase you. Use the cars for cover and just focus on getting inside. They only spawn outside so you're ok once you're past them.
It does suck if one spawns near the van you have to drill tho, but just use cover and let it focus on the bots.

Q: In the vid you didn't get many specials on Day 1, why?
Well RNGsus smiled on us and blessed us with not many specials, I think we only got a few dozers overall but not too many. I have noticed a ninja buff to specials reacently but as long as you keep it moving you should be fine. Before you say that you have to kill them, you don't.
I have a friend who did Day 1 on DW without getting a single kill.

Q: The AI keep dieing and not getting me up when I die, is the achivement broken?
Kinda sorta. Yes there are 2 AI bugs in play here. First the AI has no way to deal with the turrets so they just rambo them and get killed. Second the AI priority is bugged so the AI will keep switching between getting players up and fighting specials, stopping part way when they decide when they try to get you up. Overkill has said they are working on fixing this.
But this doesn't mean this achivement is impossible, just alot harder than it use to be.

Q: What about Winters?
Molotovs. That's my WIP solultion for him, rain down fire as soon as he's in place.
Fun fact: damage from molotovs procs Grinder.

Q: Will you be properly updating this guide/making a new vid?
I don't have an answer for that, both me and Ax (who often teams up with me for ♥♥♥♥ like this) have both stopped playing due to the Blackmarket/CO pack updates. We're both unsure of we're going to return or not.

Q: What about Grinder/Ex President?
I haven't tried Ex President yet, but Grinder is very good for this as long as you can deal more damage than you take. Muscle is a good enough subsitute for Grinder if you don't own the DLC.