Instructions
Turn on your gaming console with your GameShark enabled and open up the "Game Name" List. Locate the name of the game that has the installed cheat codes you want to delete.
Highlight the name of the game using your directional pad or joystick and press the "Action" button to bring up a list of "Cheat Code Descriptions" for that game. The action button is different on every console but it is usually "A", "X", or the "Start" button.
Highlight the code you want to delete from the "Cheat Code Description" list. Press the "Select" button to delete the code. A dialogue box should pop up that will ask you if you are sure you wish to continue. Select "Yes" to confirm. The cheat code you selected is now deleted.