1) After you start the mission arm all 4 guys and then send two around the corner from the entrance in which you will come. Send one of the other two to stand in the door way of the entrance looking to the south (bottom) of the screen and send the other to the east (right) just beside the shipping container here.
2) You will either have already intimidated the guard to the north of your two characters that are right beside the entrance from which you came, or you will have by now aggroed him towards you until he gets intimidated. Once he is intimidated bring him closer to your guys and out of the camera site and empty his pockets. Once his pockets are emptied order him to walk as close to the south western corner of the two walls of which your other two guys overlook. He should still be fully intimidated because the other two characters that you placed in the door and beside the shipping container should now be covering him.
3) After the guard is in the corner, send the two guys you had originally capture and intimidate him (the ones that were positioned beside the entrance) over to the east in between the two shipping containers looking towards the north east. From here if you wait you should be able to aggro/intimidate the two guards patrolling the area here. Once you do, order them towards you and empty their pockets. Once emptied have one character aim on one guard and the other character aim on the other and walk them back to the first guard.
4) After the three guards are together in the corner and being watched by the other two characters on your team, send one of your remaining two characters into the building to your east to shut off the camera and send the other to collect the pocket change from the guards and then into the same room as the other guy to collect the grey key.
5) Once the key is collected, double back to the entrance and head along the wall and gate past the two cameras here. Unlock the closest upcoming room and smash the cash box to collect the first of 6 piles of cash.
6) Once the cash is collected order that character to head to the east into the building with the orange and red doors and go into the room with the closest cash box. Have the character pick up the orange key and smash the cash box, collecting the money after.
7) Leave through the orange door to the south, hugging the southern wall of the building till you get to the gate. Hug the gate till you pass directly underneath the camera, then have your character make his way back into the building now directly south of you and unlock the orange door.
8) NOW, this can go one of three ways. 1ST) The best scenario here would be you entering this next room and intimidating the guard in the room. If you catch the guard outside at a good point in his cycle he should be outside the wall and hear the commotion. He will then come to investigate getting himself intimidated which then you select the guards and make them fight each other. After one knocks the other out you finish off the remaining guard and haul their bodies into the room you just came from. Locking the grey door and then orange door. 2ND) If you come out and intimidate the guard in the next room but the other guard isn't directly outside the walls, you can start to knock out the guard in front of you. Sometimes the guard outside will be cycling through his patrol and will here the commotion and come investigate. When he does you simply intimidate, knock him out and then put both in the previous room with the switch. Locking both doors. 3RD) The other scenario would be you coming into this room, intimidating and knocking this guard out. Then having to select your two guys and making them stand outside the door to the east till you aggro and intimidate the guard. Then you just bring him close to you; out of camera site, knock him out and then lock both up like the other two scenarios. After dealing with the guards be sure to break the cash box, grab all the cash from it and pick up all the pocket change the two guards drop!
9) Once you have dealt with the guard in the building and the one patrolling just outside it, have both your characters move to the eastern side of the shipping container closest to the ship. Walk them up to the next shipping container at the most northern point of this container and have them facing northeast. MAKE SURE to have them unequipped when you do so. Once in position equip them and let them aggro the guard to your north east. Send this guard north to stand on the little wooden bridge that connects the ship to the dock and have your two guys stand just to the west of it. Have them facing still to the northeast and they should intimidate the guard to the northeast standing closest to the only other boarding point on the port (left) side of the ship. Once he is, send him to come down and fight the first guard you have captured. Let them fight it out and knock out the winner. Then carry their bodies down to the building to your southwest and lock them in the room with the cash box.
10) Once you have dealt with those two guards on the ship, send one of your guys to stand right outside the red door of the building to your north and send the other to collect the pocket change from the guards and then stand outside the grey door to the bridge of the ship.
11) NOW this can go one of two ways. 1ST) you move your character to go into the room standing right beside the red door and then collect the key. After you break the 4th cash box and collect the funds send the character to go unlock the red door your other guy is standing at. 2ND) When breaking the cash box sometimes (rarely) the guard outside will hear. Here you have three choices, to intimidate and deal with him, locking him in the bridge for safe precautions. To try to run past him all the way to the red door where your other guy is standing at (NOTE: I do not think in most cases you will be able to make this run). Or lastly to either hide just to the south of the bridge or to run and hide behind the shipping container to the west of the closest ramp to the dock. Rarely will he here you break it, but in the event he does, be prepared to have one of the back up strats ready.
12) Once you have the red key and have both guys at the red door, open the door and intimidate the guard. After knocking him out place him in the room to your west, where the other cash box you already got is and where the orange key was. Collect his pocket change and break the cash box, collecting the cash from it. Now that you have placed the guard in the room to your west you currently no longer need the two characters any more. Keep the one with the grey key and send the other to enter the van. Lock the red and grey doors to the room you place the guard in (NOTE: It's not necessary to lock these doors as you should be able to escape after getting the last cash box well before this guard wakes up).
13) Once the doors are locked (or left) send the guy with the grey key to the north of the map to the locked small building up here. Have him unlock the grey door and then smash and collect the last of the cash from the cash boxes. Once this is done (if this is the character with the red key) send him to unlock the red door at the southwestern corner where the 3 guards are, if he is not the character with the red key you should be able to tell him to get into the van and he should path find directly there.
14) The only thing left is to have the remaining guards knocked out and have the last two guys get in the van!
Hope this guide helped, if it did let me know and if you guys want more guides to anything let me know as well!