Instructions
Turn your DSi on. Select the "DSi Shop" icon in your DSi's main menu.
Select the "Start Shopping" option in the DSi Shop's main menu. You will be presented with a list of games available for download.
Select the game you wish to download, then select the "Download" option to confirm your choice. If you do not have enough DSi points to download the game, you will be asked to add more. Do so using the information on your debit, credit, or DSi points card, and the download will continue.
Select the "Back" option after downloading the game to return to the DSi main menu. You can now play the game by selecting it in the main menu.