Why downgrade? 9.2.0-20 allows for custom firmware to be set up and provides the most compatibility with homebrew and 3DS flashcarts (such as Sky3DS or Gateway).
This is a guide written by DsHacker14 that shows you how to downgrade your Wii from 4.1 to any version below that. Regions When you downgrade your Wii you will have to downgrade it to the same region your wii is right now. To find out what region your Wii