Instructions
Insert your Action Replay memory card into the GameCube's second memory card slot.
Insert the Action Replay disc into your GameCube and turn the GameCube on.
Select the "Action Replay Codes" option on the Action Replay main menu. Highlight the flag representing your region and select the "Pokemon XD" game from the list of games that appears.
Enter the codes that you wish to put into your game, or select codes from the preset list. Press the "Start" button when finished.
Eject your Action Replay disc from the GameCube and insert the "Pokemon XD" disc when prompted.