you put the sd card and the game you want to backup into the ars sd and game cart slots respectively then you start up the dsi and start the ar. then go to saves and choose backup game save. type in a game name and a save name, then your done. heres a save converter so you can convert your saves to save pokesav can use
http://software.uniquegeeks.net/dnn/Software/ARDStoSAV.aspx