You won't take a steal approach with this side mission. You'll go in hot with your helicopter to extract an undercover MSF soldier embedded within Camp Omega.
As the mission begins, shoot everything that moves while your pilot tries to locate the friendly. When he sets off a flare revealing his location on the east side of the island, provide him with cover using your rifle. You can use the grenade launcher if you need a tough problem solved in a hurry.
The friendly will ask for support as he makes his way to the extraction point. Keep switching between your rifle and grenade launcher, keeping an eye out for jeeps, infantry and watchtowers. As soon as a truck blocks his path, start picking off stragglers. The friendly will back up his jeep, so use this opportunity to clear the area just before the helicopter lands.
Once you reach the extraction point, keep a keen eye out for anti-aircraft guns, RPG soldiers and just regular infantry. Engage anything and everything until your friend's jeep is taken out. No worries, he's still alive. When you kill the last of the soldiers, get out and sprint toward the friendly.
Don't pick him up. Instead, grab the rocket launcher next to him. Take out the advancing armored vehicle and be sure to pick up any infantry stragglers when it's down. Grab the friendly and get back in the chopper.
The job isn't done yet, there's a helicopter on your six. Take it out quickly before it takes you out. When the coast is clear, enjoy a moment with your old friend.