If you still have the downloaded file on your computer, you can simply copy it and paste it into the game folder on his micro sd card. You may see a game listed with .sav after it. That is not the game file, that is the information saved from his game - his levels, characters, etc. That .sav fileis necessary to continue his games, but you need the game file to play it. If you don't have the game file on your computer, you'll need to go back to the website you got it originally from and download it agian.

Hope it helped,
~Sarge