Dec 2008 - that link is no longer available. I found the answer at http://www.howtomendit.com/answers.php?id=42162
1. Remove height selector slider (it just pulls off)
2. Using a flatblade screw driver, pry top cover of base (right or left side) up and away from the black (or dark gray) base assembly.
3. Once one side is off, pull sideways till the entire cover is off.
4. Remove lower plate by prying it off of the base assembly. There should be no screws holding it on.
Now you can work on the belt and brush roller.
It is easiest to first put the belt on the brush roller and put the bottom plate on. Then stretch the belt onto the motor shaft and reassemble the base. If you need any more help or parts, my email is arctic@worldlynx.net
R. Cressman, December 2008