You need to buy some hardware for this to be done. You need a device to store the game on, either a Flash Cart or a Card adapter. I have a M3 with a 512mb CF Card. You also need a 'PassMe' device, I recommend getting a Passkey2, or the new Datel Max Media Launcher. These devices allow for the game to be laoded from the GBA port of the DS instead of the DS port. *Update* I have just remembered that the Passcard from the M3 team has been released, I highly recommend getting this as your PassMe device!
why buy M3? Just go to supercard.cn and look for better and cheaper options. M3 costs way too much to do the same as some others. cheers
Cheaper yes, better no. Supercards are made from cheaper components (hence cheaper price) and are also prone to slowdowns when playing GBA games. Also don't forget how Supercard started, by copying the GBA Movie Player - which was developed by the same people behind the M3.