Get the loader.dol, rename it to boot.dol and put it in /apps/Nintendont/ along with the files meta.xml and icon.png.
Copy your GameCube games to the /games/ directory. Subdirectories are optional for 1-disc games in ISO/GCM and CISO format.
For 2-disc games, you should create a subdirectory /games/MYGAME/ (where MYGAME can be anything), then name disc 1 as "game.iso" and disc 2 as "disc2.iso".
For extracted FST, the FST must be located in a subdirectory, e.g. /games/FSTgame/sys/boot.bin .
Connect your storage device to your Wii or Wii U and start The Homebrew Channel.