I had a bit of a bitch with the Ocelot crew in that little room, aswell

What I did is: Hid under the bed with the AK pointed at the door in first person. You blow the head off about 4 or 5

Then: 1 is on the roof of the little room you're in

1 is over the other side of the area, behind the big wall

1 can be lured close to the room by making sounds.
I think you can do this guy by shooting out the window, aswell

"Now TV's all about format these days isn't it, and I've got a new type for you right here. Its me and Paris Hilton driving around in a car.... Now I know what you're thinking, but she's in the boot!" "So you see, 'Ring around the Rosey' refers to the horrible symptoms of a terrifying disease, a disease which.....a disease which....ZIM! Theres a Pigeon on you're head. You have 'Head Pigeons'. get to the Nurse before they spread to the other children." "Get off my lawn Cookie Beast!" --Invader Zim