you can do it, but you have to downgrade the ios and the system menu first. I don't have all the steps handy on me, but I did just do it for a friend last week. Takes about 45 minutes from start to finish. Just google "downgrade wii (version number)" it should come up in the first couple links there.
I did all of this tutorial on girlfriends NEW wii and it worked
http://gwht.wikidot.com/usb-loader