i would stay away from them becasue this is a good way to brick your wii...
Hey Guys, any1 know how to set up a custom theme for wii?
emuhack is correct. this is for advanced users who know what they are changing in the system and have taken precautions to be able to bring their wii back from the dead as this is an often occurence.
Don't do it. No theme is worth the cost of a Wii replacement.
Not really doing much Wii stuff these days.