Instructions
First Pistol
Go to Level 2: Derelict apartment block.
Go to the very top until you see a machine, two keys and a door.
Pull the lever on the machine to make the elevator work.
Go into the elevator and select #2 to go to Floor #2.
Jump over the big gap and go through the door.
Open the closet to get the first pistol.
Second Pistol
Go to Level 19: Van Croy's apartment.
Attack The Cleaner, who will blast a hole through the wall.
Repeat Step 1 until the The Cleaner has made a large hole in the wall, revealing the second pistol.