Idea#1: If Kim and Kareem could argue and/or fight in a way big enough to draw a few guards over then we can move on them. Once they got close, Kim can give a huge fake sneeze and then I can toss my flashbang grenade and blind the guards that are close by (Kim and Kareem, after the sneeze - would know the flash is coming and can shut their eyes - at least I hope that could work, I don't have my book with me at the moment to reread about flashbangs). After the flashy kaboom, I move in with the assault rifle on the blinded guards while you guys pull your weapons and dive for a better position to finish them off.
Just as this is happening, Ghost can take out the guard on the tower.
Idea#2: Another idea is to check and see if opening the back fire door would set off an alarm system. This would require us to see IF the door could be opened from the outside/back and to have Ghost see if alarm units are present in the building (like flashing/noise alarms, sprinkler systems, etc.)
If it looks possible, we could use that as a distraction and move from there.