Instructions
Remove your Action Replay device from the DSi, then connect the Action Replay to your computer with the included USB cable.
Launch the Action Replay Code Manager software from "Programs" in your "Start" menu. If you have not already installed the software, use the disc included with your Action Replay device to install the software onto your computer.
Click on the "Official USA Action Replay Codelist" option in the "Subscriptions" window. This brings up all of the codes available for American DSi games.
Select the game with the codes you want to add to your Action Replay device then drag-and-drop them into the "My Codelists" window. Repeat this process until you have all of the games and codes you want for your Action Replay.
Click on the "Commit Changes" button near the top of the Action Replay Code Manager software window. This will save the changes you just made. Disconnect the Action Replay device from your computer when the process is complete.