I softmodded my 3.xx Wii back in 2009 using this method:
1] Update your wii to the latest "homebrew friendly" firmware (If on <4.2 currently).
2] Install the Homebrew Channel & Bootmii onto your wii.
3] Restore the trucha bug on your Wii by installing a patched IOS236.
4] Install custom IOS...
