what no all he need is a double dash disk (if he have a wii in this case) put it in the wii and kaboom you are playing without hombrewing your wii (cuz the wii is backwards compatibility)
...Ok you won But, BIG BUT, you can still play gcn in black by changing the disk container (idk name) but u cant use da gamepad
CONCLUSION: Download Dolphin emulator and a rom and there you go, it a bit laggy but better than nothing
KIDS WITH A SWITCH; NOOOOOOO ITS ME; LET ME GET THE LEFT SCREEN; KIDS WITH A GAMECUBE; LET ME BE UP AND YOU DOWN THEN WE WILL PLAY IN MUSHROOM BRIDGE; YES BRO