Objective 1: Ambush The Communications Vehicle Guards
Actually I already have the gut feeling that this will happen, and I miss Anya since the first game so it's good to hear her again. Run straight to the truck and move slowly when you get close to the first guard. Break his neck, get the rifle and move under the truck. Aim at the two guards in a way that both of them will be shot by just one fire.
Objective 2: Send Radio Signal For Rescue Helicopter
After you killed the three guards activate the radio signal and head to the extraction zone.
Objective 3: Move To Extraction Zone
This is the hard part, after you activated the signal the place ahead will be swarming with enemies/choppers/APCs. I found two ways for this objective:
1) After you've sent the signal face right, cross back to the other side of the road and crawl to the south. When you think your far enough from the communications vehicle run (that's right RUN) south until you reach the land mines.
2) After you've sent the signal face left and run (that's right RUN again) straight to the open space until you can see the lake. Don't go further coz there are APCs on the lake side, instead head to the trees south and either shoot or sneak the enemies there (about 3 I think). Then head to the land mines.
There's only one way to the extraction point & there are LOTS of bad guys here. I assume you already saved your game, hide under the bushes and wait for them to leave the south area. Most will leave while some will stay and patrol the area (most of the time 5 enemies). When that happens aim your rifle on the 5 guards and also the guard on the southern tower. When the south is clear (sometimes a group of guards still go back) crouch your way to the tower and climb the fence. Head to the chopper.