How to transfer old sd card that has modded stuff to a new 3ds

I need help my friend's old 3ds was broken badly but they had saved everything onto the sd card (16G) and we got a 3ds that someone used to use that they had modded then system formatted and given to us. We thought that if we just put in the SD into the new ds everything would just load back on but it hasn't. But when i hold start and power button it shows with that screen so I know It's possible. What do I do so I can load all their games n downloaded content back on the new 3ds? I don't know much about modding and stuff but I wanna help my friend...