Things You'll Need
Instructions
Download Pokesav from the Project Pokemon website.
Open the program once it has finished downloading.
Change any options you wish to edit. You can edit your name, the names in your bag, the date you started the game and, most important, the stats of your Pokemon.
Press the "Action Replay DS Cheat Output" button to create the code. You can either input the code manually into the Action Replay of your Nintendo DS, or you can connect the Action Replay to your computer and input the code through the "Action Replay Code Manager."
Start the game and select your "Pokemon Diamond" save file. Press and hold the "L" and "R" buttons to enable the Pokesav changes.