One of my sd cards didn't work, but I didn't have to do anything with the other one to get it working, just get the latest AKAIO 1.9.0 and a patched rom
You first need to know the reason why you can edit the save games from the 3DS, it's because you have to put the game cart into some usb device.
You can't put a demo into some usb device.
+1 Mario Kart 7
+1 Super Mario 3D Land
+1 Legend of Zelda Ocarina of Time 3D, The
+1 Super Street Fighter 4 3D Edition
+1 Tetris Axis
Own them all, play them all, love them all.
I love pushmo (pullblox in Europe), you can spend really much time with it and you can also make your own levels.
I also like playing freakyforms, you have to be creative to like it though.