Instructions
Visit the website for the NDS Action Replay XML Code Editor at projects.sappharad.com/tools/ardseditor.html.
Click the download button to download the application. Save the file to your desktop.
Open the file you downloaded, which is a compressed file. Click the "Extract" option in the Windows folder and extract the application to a place you'll remember on your PC's hard drive.
Open the NDS Action Replay XML Code Editor application.
Click "File," and then "New" to add a game to the list. You can then add codes to the game in the "Code name" section, and enter the code itself in the "Code data" field. This information is added to the Action Replay XML file.
Edit a code for a game that already exists by opening the game's folder in the app, clicking on a code and altering the information in the "Code data" field.