I don't have a wii so I can't really help you there.
But from what I read with a quick google, you need to convert the file to a format compatible with the wii and load it through the SD port. Not really worthwhile.
I am writing this from Wii (Yay Nintendo). In genral I haven't been online on my wii for the past two weeks since it broke and had to send it in to the company. The thing that stinks is when I am trying to reply is I can only reply by using quick replies and not able to click post replies ( at the top) at all.