from post #32
If your on system menu 4.2 and no longer have vulnerable IOS you need to use bannerbomb to run DOPIOS MOD running on IOS 250 to install a clean IOS, IOS 36 shuold be fine that will allow the main hackmii installer to run. If bannerbomb isnt working you have either a the wrong version or b running from wrong location. Get the hack 4.2 pack from ZXZeros guide if on 4.2 for a working version of bannerbomb, if your on 3.x get the update to 4.2 pack from zxzeros guide and use that version of banner bomb, both require running from a different place, but you will need them to run DOP IOS MOD to reinstall a vulnerable IOS, if on 3.2 you might want to install a clean IOS 34 as it isnt used by anything.
if you can't get that to work then replace the boot.dol on the root of the sd card with wad manager boot.dol and install IOS36 v1042.wad from NUSD