Instructions
Turn on the PS3 console by pressing the "Power" button on the front.
Open the "Call of Duty: World at War" game, and choose "Multiplayer" when the main menu appears.
Select "Zombie Mode" as the type of game you want to play. Choices will include "Competitive," "Zombie Mode" or "Co-operative."
Select a mission, and go into "Settings." Open "Game Rules" and select "Enable Death Card Cheats" to see all the death cards you have collected in the game. Choose the ones you want to use by clicking on them.