For a good portion of this mission, you simply have to listen to Campo's directions and follow where he goes and you'll be safe.
First, you'll have to take out the four lights down below so that the chopper can land. If you manage to shoot all four with one bullet each, you'll get a chievo/trophy. The trick here is to aim just about the light at where the light meets the wire so that the bullet will fall a little and hit the light. After the squad has landed, you'll have to move to the corner of the building. Wait for the squad to move ahead and for Campo to mention an enemy ahead. Then look ahead of the squad and up the balconies a couple of floors. You'll see one guy standing around. Take him out.
After you've killed him, you'll have to go to the back of the building and repel down. For a little bit, you'll just follow Campo but don't shoot anything and shadow him completely. Go over a wall and pull Campo over, then he'll say something about a guy watching the street that you'll have to take out so do that. He'll be up a few floors on the left.
Again, after this you won't shoot for a bit until you follow Campo up a ladder to another roof. From here you'll have to cover the other squad. You'll be asked to take out a couple of enemies. These two will be on the right side of the road, just standing still. Line them up so that you can get two kills with one shot and you'll get a chievo/trophy for it.
Follow him down a ladder and use the overpass to get to the other side of the street. Soon, you'll enter a building and have to kill an enemy with your knife. I'll save you some time, don't crouch and sneak up on him. Just walk right up to him because your attempt is scripted to fail but if you are crouched down, it won't be able to trigger the sequence and it will kill you. As soon as you kill him, some PLR will come up the stairs so just follow Campo at a sprint.
You'll move through the sewers for a little bit and then climb up a ladder into the streets. When you get to the streets, try and take cover behind a destroyed van because you're about to get into an unavoidable firefight. There are only a few enemies here so just stay safe and pick them off when you can. Make sure you aim for their lights.
Get rid of these enemies and then follow Campo into another building. You'll come to a room with a chair and camera and some blood on the floor. You'll have a chat on the radio but we'll they are chatting, you should take cover by the windows leading into the next room. After the talk on the radio ends, you'll be attacked from this room by a few enemies at a time. If you keep shooting, you should be able to keep there from being more than one or two enemies in the room at a time. Clear the room and then head downstairs and across the street to the mall.
Follow the squad through the mall and then you'll split up again. You'll head up to another roof while the rest of the squad heads out to get Al-Bashir. Climb up the ladder and head into the rooms at the top. Go prone and protect your squad on the ground. This sequence is somewhat long but fairly simple. At various points, you will be attacked by troops on the ground so just back up or use the walls to the side for cover. Aside from troops on the ground, you'll have to deal with a couple of enemies on balconies and toward the end there will be a couple of enemies with RPGs on the roof of the building. Just keep shooting and try to keep the enemies numbers low.
Once they say that Al-Bashir is making a run for it, you'll have to turn right and run over the rooftops toward the street. You want to switch to your secondary weapon and just hip fire at his car as it starts from the left and heads right and takes a left at the intersection. If you manage to stop him, he'll crash into a light pole after he turns. Jump down and head to the car.
Campo will pull him from the car and then you'll have to cover him. Immediately turn around from the car and you should see a wall and the lamp post that he crashed into. Just stand right up against that wall which should just leave your head poking out. Keep thinning the enemies and then when you feel like you've got a good chance, run towards the doors to your left (where the Defend marker is located). Get inside those doors and poke your head out a little at a time and kill enemies. After a little while of this, Campo will tell you to come through the door and meet up with him.
After the talking, you'll have to defend them again from a group of enemies entering on your floor from the left. If you take aim down the hall, you may be able to take out two or three of them before they even reach cover. Clean up any that you missed and then you will have to make your way out of the mall. Wait for Campo to go first and if you are making good progress without being shot at, just keep going right outside but if you are taking damage, there is a large potted plant to the left that you can go prone by and be pretty safe. Once healed up, head outside.
Once you get outside, find a good cover position that will protect you from the building off to your right. At this point, you just have to wait, you don't need to kill anyone. Keep waiting until your squad gets on the chopper but don't follow them just yet. Wait until Cole yells at you to "come on" and then run into the chopper. Otherwise you'll run into an invisible wall and get shot. Once on the chopper, the mission ends.

