1) Run to the first fuel room and on the way shoot everyone who gets in the way.
2) At the fuel room, when you first come in turn to your right and there will be a guard over there. Find the key card and get out by going up the stairs. In the hallway there will be a guard on the right and two on the left (if they don't run down into the fuel room when they here you shoot someone). Shoot the guy on the right and then the guys on the left. Then run for the door. Once through, shoot the guy on the bridge and then go through the other door. Shoot all the guys you see and then aim up the steps. When you see a guy at the top of the steps shoot the barrel next to him and it will kill him. Then run up the stairs and run around the corner shooting. Hide behind one of the crates and shoot at them.
3) In the second fuel room get the key and run up the stairs. In that hallway, there is one guy to the right and two to the left. Shoot the guy on the right and then the two on the left. A guy might come out of the door on the left so wait a second to make sure he doesn't come. Then go through the door on the right. Shoot the guys on the bridge and then run through the other door. Shoot all the guys and then run up the stairs and turn left. Shoot the guys in this hallway and run into the third fuel room.
4) There might be a few guys in the room so shoot them and then get the key. Run up the stairs and you will see a guy hiding behind a crate. Shoot him and strafe to your left. A guy will come from the left, shoot him and then go out in the middle and there will be a guy on the right. Shoot him and then turn right and go through the door. Shoot the guys on the bridge and then go to the other door. As soon as you open it start shooting. Run in and strafe to your left and hide behind the crate. Shoot the other guys and run up the stairs. Then go in the fourth fuel room.
5) When you go into this room there might be a few guys, so shoot them.
6) Select your camara and take a picture of the satellite. Run up the stairs (you don't need a key) and go through the door. As soon as you open the door charge Ourumov and just stay right behind him so he will open the doors for you. After you go through the second door while following Ourumov, take off and run for the elevator.