After going through the gate when chasing Shetland, the first bomb is directly to the left of the gate that you enter. Go left through a little crevice and you should see a red light flashing. Go to it and disarm it. When you do that, one of Shetland's gaurds will walk up the stairs. Kill him. To get to the second bomb, go up the stairs. Turn left then turn right and look straight ahead. You should see another red flashing light down below the walkway. Hop over the ledge of the railing and disarm the second bomb. When you are done disarming the bomb, jump on to the railing and pull yourself up. Two guards will be to your left, walking on the walkway. They will probably hear you; get ready to kill them. It is fairly difficult to kill them without losing a lot of life, or at least dying. After you kill them, go down the walkway to the back wall. About halfway you will see another red flashing light. Jump across the little gap and disarm it. A guard will come through the back door right when you disarm the bomb. Kill him, then go through the door and meet Shetland. You will then have to make a critical choice; note: pull the trigger. It would be a good idea to quicksave the game whenever you disarm and kill the guards.