Things You'll Need
Instructions
Getting the Tools Ready
Download the GameCube backup launcher Xi (see Resources for link) and extract the contents of the zip/rar file to your computer's desktop.
Insert the SD card into your computer and copy everything from the "Xi" folder you downloaded to the root of your SD card.
Insert the SD card into your Wii and start up the console.
Installing the Backup Launcher
Load up the Homebrew Channel on your Wii console.
Select the "cMIOS-res1-Installer." The screen will go black but don't be alarmed; it may take a moment to load.
Press A on the Wiimote to start the installation. Select "WAD" installation mode and it will begin.
Once it says "Success," restart your Wii console.
Playing the Game
Insert the GameCube backup disc of your choice and select Homebrew Channel again.
Select and run the GameCube backup launcher Xi.
With the game in the console, it should now load up and let you play the GameCube backup.