Go to Wetwork and onto the stair case in the ship on the front of the ship. Climb the stairs and then face over the stairs at some pipes on the wall. Run and jump on them, but make sure you go towards them. You will now float above the doorway to the stairs. People can still shoot you from under the stairs, but make sure you dont shoot before they walk in - it keeps the element of surprise. This cheat is great for free for all's and works on old school or not.
