Crawl under the pipeline, then across the road and proceed towards the guard tower mentioned above. Somewhere near this construction you'll probably have to eliminate one more guy hanging around (#15). Afterward, squat and sneak carefully to the left. By-pass this yellow painted building you have on your left.
Behind it you maybe see this pair of morons hanging around the cam-net - if you didn't kill them earlier (#16). If they're still alive, you can try to finish them off right now - shoot fast and accurately, don't let them raise the alarm. Afterward, move towards the white dot on your screen and by-pass from the right these gentlemen being drilled on the square in the middle of the camp.
You'll see three enemies when closing to another yellow-painted house - ther're standing a little further and in front of you. Don't attack them, just use this small stairs you see on my picture (#17) to sneak inside the building. Go crouch and stay away from the windows again.
Behind the second entrance to this hut you'll approach, there's a shooting range organised among the sandbags with some dudes practising the shooting on it (#18). They use silenced weapons and that's why the sound is quite untypical. Don't attack them! Just ignore them, go crouch or even prone, exit the house and sneak to the right, towards the white dot being visible on your screen.
After a while you'll see on your right these three bad guys (#19), who you've ignored when entering the building. And now don't attack them too - they're blind and deaf and shouldn't see you even now, when they stay with their faces rotated in your direction. They won't hurt you.
You'll get to some barrels - sneak through the hole in the fence you can see behind these barrels (#20). Afterward, sneak under the pipes to the left.
You're almost in place. Now you have to move upstairs and get to this yellow painted building which you see on my picture (#21). But there's a guard patrolling around this house and at this moment he should walk in your direction! Don't let him see you and quickly hide on the left, behind this white pillar of the silo - you can see its part on my picture. When you're hiding there, look at the minimap and observe the current position of this guard, which is marked on this map with a red dot. When this guy is walking away to your left, you can move to the stairs. Go upstairs and enter the building.
On the table in the corner of this house you'll find the documents, the data you have searched for (#22) - take them. Now you have to get out the camp undetected. And it would be probably easiest to do this by going back on your own tracks, but it's not so easy.
While exiting the house pay attention to where is currently the opponent who was patrolling around the building! Exit the house when this guy passes the stairs - you can shoot him at his back then. You should use the ladder to climb up the silo which you see on my picture (#22).
Go crouch when you're on this silo and turn right. You'll see a guard standing on the next silo - use your sniper rifle to take him out (#24).
If you look to the right and downwards now, then maybe you'll be able to spot another guard hiding in the lodge near the road (#25). Focus on the target, pull the trigger and he should be dead.
Now take a walk to the place marked with a white dot on the silo, where lies the body of a guard killed a few seconds earlier - be careful, though. On your left and on the ground level you'll have the shooting range with soldiers practising the shooting and three "blind men" near it (#26). I'd suggest to leave all of them a-loin.
Go crouch, enter on these pipes you see on picture (#27) and visit all the places marked on your screen with white dots, by moving along these pipes. Be careful, don't fall down!
Shortly after getting on these pipes you'll see a truck passing you by the road running under the tubes (#28). Don't bother about the driver, he's blind in the same degree as others are - I'm sure he'll got a car accident soon... All the time ignore completely the soldiers being drilled in the middle of the camp. Just sneak further along these pipes.
Somewhere along the line O'Neill will give you a hint via the radio to turn right and jump down these pipes onto the roof of some wooden barrack (#29). Do it, then jump down this roof to the ground.
Afterward, use the wooden crates to jump over a white wall (#30), go under the watch tower and run towards the place marked with a white dot outside the camp, in order to complete this mission.