You need Anesthetic for this trick. As you start the level by the elevator, drop you axe and look at your map. You will see a room to your left side with an attention point. Move to the door on your left side, but do not open it. Wait until the guard moves aside, then open the door and move calmly towards the room. Pick the lock and open the door. Grab the keycard and save the game. Get out of the room and knock out the guard with the Anesthetic. Take his clothes and hide his body in one of the bathrooms. No one will find him there. Look at your map and you will see a room directly in front of the server room. Its door is marked red. Run towards that door and make sure that the guard does not see you. When you reach the door, open it with your keycard and put a bullet in the server cooler. This will overheat the server and cause the administrator to run towards the server room and enter it. When he does so, enter the room after him before the door is locked again. Knock him out with the Anesthetic, plant the bug, then calmly get out of the room. Save the game at this point. Run towards the great window leading to the skybridge. Smash it by puting a bullet into it. Ignore the guards outside and just run towards the exit to complete the level.
You will need a silenced pistol and Anesthetic for this mission. As soon as you start, go into the room to your left that has a "!" blinking in it. This one is the closest blinking one next to you on your map. Once inside, shoot the camera aimed at the coffee pot. Then, go back into the elevator and get the Anesthetic ready. Watch your map for the system administrator to walk into the room with the camera that you shot. While he is standing looking at the camera, sneak up behind him and use all five slots of Anesthetic on him. You only have about five minutes to complete the next part; and must be quick. It is difficult, so run when you can. Take his clothes as soon as he is out cold. Run to his office and grab the key card. His office should be the room with the "!" in it on the far left of the map. Run to the office that has a "!" blinking in it with the yellow door. This room should be at the top of your map; it is the left room (and not the right one). Plant the bug on the computer server. Run to the big window and shoot it with your silenced pistol. Then, run all the way to the exit. It will be difficult with the guards there, but by now the administrator is waking up and about to tell the guards someone took his clothes. The trick for this mission is not to get noticed or shoot anyone. Also, in order to walk faster, walk backwards.
