Well, sure... But remember, next time post this in General Discussion and not Nintendo Gamecube.
First, you find a picture you like. For example, I like this picture here...
http://www.el-mundo.es/navegante/ima...1018520860.jpg
That up there is a link. You copy that thing and go to
User CP up there and then go to
t Options and scroll down to see Avatar or Change Avatars.
So, User CP> Edit Options> Avatar. It's very simple. Clcik on "hange Avatar" and paste the link that I told you up there. It's very easy.