1. Break communications link to bunker: medium 
2. Disable Spetznaz support aircraft: easy, medium 
3. Gain entry to bunker: easy, medium 
4. disrupt all surveillance equipment: hard 

You were planted here in mission 4 (surface), so this environment should be more familiar. Bond needs to go to only three areas to beat this mission in the medium mode. Start by killing three soldiers who are all carrying Klobbs. Take the bounty. Switch to the Klobb, it'll make you feel good. Now follow these basic steps. Stay on the main road until you reach the third road on the right. Take it past the empty bunker on your right, to the dead-end with a single bunker on it. Kill the surveillance camera and enter, and then kill the military commando just inside the door. Pick up the comms room key and his gun. You'll need the key later. 

Head back to the main road, but make sure to shoot the borsch out of the Russian dudes who've heard all the racket. When you reach the main road, take a right, at the fork just before the satellite, take a right and follow this road to the satellite building. Run and you'll miss all the guys who want to join in the killing. Run straight up the stairs, locate and shoot the surveillance camera (at the second tier), open the door at the end of the stairs and you'll see the communications computer console. Smash it. Text will tell you when it's completely destroyed. Now leave (and you'll have already been joined at this time by about five Russian dudes (just kill them). 

Two objectives left (in the medium mode), and to meet them you need to take this path. In the hard mode, you must go to the enemy bunker (yucchh). There are at least two camera in that area, and you should be fully loaded and in good health. You will take damage here. Now go back to the main road, and take a left at the fork and head toward the ventilation shaft. Now if you take the next left, you'll go to the ventilation shaft, which is perfect if you're in mission 4. But here, before you reach the ventilation shaft, take the right at the fork, avoiding the ventilation shaft. By taking a right, you'll run straight to the helicopter and the bunker. Switch to the timed bomb, plant on the helicopter, walk far away and make sure the helicopter is blown up. A few stray Russian guys will show up to drink vodka with you. Usually you can just stray left to avoid them, but we usually kill them. Kill them (hey, why not?). Enter the bunker. You're done.