You have to have the Wii and Wii U connected to the Internet, and an SD card. It seems to do some kind of online verification thing with both consoles, and then you use the SD card to transfer the saves (I think). My Wii U seems to now be redownloading everything.
#9192329, By harriselhoff Wii U
harriselhoff 202 posts
Seen 41 minutes ago
Registered 9 years ago