I took the info from the link below and shortened it up. I hope no one cares I use their links.
http://gbatemp.net/index.php?showtopic=81650&st=60
What you need:
Mario Kart ISO
Program PPF-O-Matic:
http://www.sospc-en-ligne.com/downloads/pdx-pom3.zip
PPF Patch:
http://uppit.com/TZZ6W2
Wii Update Remover v1.0:
http://wii.waninkoko.info/
Launch PPF-O-Matic
Open MK.iso
Apply PPF Patch
Use Wii Update Remover v1.0 on patched ISO
(Optional) Use WiiFrii v2.3b to make NTSC compatible.
Burn with Nero (Or whatever you know works)
Play on Wiikey 1.9b
Play Mario Kart on Wiikey 1.9b - Remove Error 001
