Instructions
Insert the Codebreaker game disc into your PlayStation 2 console and turn the power on.
Highlight the "Select Cheats" option on the Codebreaker main menu and press the "X" button.
Highlight the game you want to play and press "Right" on the d-pad to access the list of cheats.
Highlight the cheat you want to enable and press the "X" button. You can enable as many cheats as you want.
Press the "Start" button to return to the main menu. Highlight the "Start Game" option and press the "X" button.
Remove the Codebreaker game disc from the PlayStation 2 console. Insert the game disc that you enabled cheats for and press the "X" button. The game will be loaded and your selected cheats will be activated.