Is there ANY way to install the Hombrew Channel on Wii System-menu ver. 4.0U????

If thats not possible, is there a way to "backtrack" to an earlier version??? (if it helps: I've had this Wii since Menu Version 3.0)

Yea you can and there's a great guide at http://www.modwii.blogspot.com
the33dude338 years ago
It's called the bannerbomb exploit. You could go to http://bannerbomb.qoid.us/ and follow the directions. Then you could backtrack to a previous version using the http://wiibrew.org/wiki/AnyRegion_Changer AnyRegion Changer, but you have to be sure you don't play around too much or you could possibly brick your Wii.