How to Install the Homebrew Channel on the WII U – 2018
Note: The two files you need are below. Remember An SDHC card will not work with Super Smash Brothers Brawl. You must have an SD card that is 2GB or less.
HackMii Installer v1.2: https://bootmii.org/download/
Smash Stack: http://wiibrew.org/wiki/Smash_Stack
Once you have Homebrew installed and running on your Wii U, you can now go and play emulators and backups. Down Below are my two videos showing you how to Play Gamecube games and other emulators (GBA, N64, PS1, etc).