Instructions
Select a map that contains a prone elevator from the "Map Selection" screen in the "Multiplayer" section of "Call of Duty: Modern Warfare 2." Maps that contain prone elevator glitch locations include Underpass, Favella, Karachi and Derail, among others.
Locate the area where the elevator glitch occurs. If you cannot locate this area on your own, ask a teammate or another person you are playing the game with online. These glitched areas are different depending on the level you've chosen. For example, in the map "Underpass," the glitched area is directly beneath the door with the speaker above it. In the map "Karachi," the glitched area is on top of the dumpsters.
Walk directly into the glitched area, facing either the door (in the case of "Underpass") or the wall (in the case of most other maps. Use the left directional stick on the PS3 controller to rotate to your right.
Pause the game with the "Start" button. Choose "Options" and change your controller layout to "Legacy Southpaw." Press "Start" again to return to the game.
Press the "Circle" button to move into the "prone" position. Continue to press "Circle" to go between "prone" and "standing." As you do this, use the left directional stick to slowly strafe to the left. When you reach the appropriate position in the glitched area, the "prone elevator" glitch will activate and you will float about the level.