yeah, i suggest what the above said.
keep in mind, though, if you have some DLC (ex. SMM stage DLC) you need to go into FreeShop, then go to your games tab, delete the DLC, and then download the DLC again, and it'll fetch all of it. This also works with StreetPass Mii Plaza and home menu themes But uh, obviously we had these download keys legally beforehand, right? Yeah, we totally did.