Instructions
Power down the Game Boy Advance device. Remove any games already in the device. This includes Pokemon games.
Insert the Action Replay cartridge into the Game Boy Advance. Insert the Pokemon game cartridge into the top of the Action Replay device. Push down gently until the game clicks.
Power on the Game Boy Advance. Wait for the Action Replay to automatically start. After the title screen, it will recognize the game and load the title.
Confirm the title with the "A" button. If it is not the correct title, press "B" and a full game list will load. Scroll down to the Pokemon game and press "A" on the game title.
Use the "D-Pad" to go to the "Select Codes" list. Press "A" on each code entry that you want to activate. The code has a brief description and then an "On" or "Off" icon.
Use the D-pad to scroll over to the "Add New Codes" section to add extra codes to the game. Code Junkies is the official Action Replay website and hosts codes for multiple Pokemon games. Use the D-pad and the on-screen keyboard to insert the new codes.
Press "A" on the "Play Game" icon to load the game with the codes activated. Now the game will load as normal with the extra codes.