Any guides to clearing a Wii of all homebrew?

I looked everywhere but can't seem to find any. HBC's uninstall guide says to just uninstall it from the data management page, but it can't be that simple, can it? I would like my Wii to be "legit" before the Wii U comes and I do my transfer so my Wii U has all my saves and shop games

All I have is HBC and two apps. Do I need to flash the NAND I backed up before I installed al this? Wouldn't that erase all the save files and stuff I've accumulated? I used the bannerbomb technique with HackMii, and used Bootmii as Boot2, I think, but removed it because I didn't like the annoying bootmii menu.

If you run HackMii Installer again and use it to uninstall BootMii/boot2 and HBC, that'll get rid of most traces, assuming you never messed with IOS patching or cIOS. However, you should note that Nintendo will always be able to detect that HBC was installed at one point, and also that there is no indication that having homebrew will prevent any WiiU transfer process from working; nothing official has ever stopped working because of homebrew in the past.