Phase 1 Clearing the west side of the riverSelect all your men, run around the corner of the building that is near you and shoot the guard who is walking in south east direction. The other two guards will hear the shooting and take a look. Shoot them too. If you practice this a while, you should be able to do this without catching any shot yourself. Also note, the higher your screen resolution is set, the more time you have to respond. Take a look at this map.
Phase 2 The first crossing of the riverRun with your marine to the river side and inflate your boat.
Phase 3 The second crossing of the river/clearing the campWhen the patrol boat has passed, inflate your boat again and bring your sapper and driver to the other side of the river, just where you sniped your first guard (take a look here). Click at the position where you want to have your boat and don't wait until it gets there, because this is a waste of time! In the mean time, climb the wall with your green beret and active the ladder so it will move down, and then crouch. Now you can climb the ladder with your sniper. When he is up the wall, crouch to other side of the platform and snipe the guard who is walking inside the camp (see here.) Climb down the ladder that leads to the courtyard of the camp and snipe the guard at the fence (see here.) Then, go inside the escape truck with your green beret and sniper.
Phase 4 Getting rid of the patrolBy now, your boat should have arrived. Unload your men, and let your driver crouch to mark X at this map. Crouch with your marine to the escape truck and crouch with your sapper to the fuel tank you have to blow up. (The marine might take his boat, though it is not needed any more). Now wait until the patrol that walks its round north to the position of your driver turn its back to your driver. Then, stand up, run to a place just behind them and kill them with your machine gun (see here.)
Phase 5 Finishing touchGet a handle at the crossing gate with your driver and double click, so he will run to open it (take a look here.) Then run to your escape truck and move it on the road in such a way that it is facing south-east wards (take a look here.) Now, let your sapper set its time bomb [4, b] and run inside the escape truck. Drive the escape truck to the exit point with your driver (just follow the road in the south-east direction.) Note, that if you do this fast, you might reach the exit point while your time bomb has not exploded yet. You get a screen with a few options (continue, quick load). Just choose the continue; the time bomb will explode within a few seconds.