The instructions on changing the belt are in the owner's manual. Basically, turn the vacuum over so you can see the bottom. There are 2 screws near the rollers(wheels) that need to be removed. Then release the 2 hooks on each side of the rollerbar guard. Lift the rollerbar to remove the old belt. Put new belt on rollerbar and loop belt around the motor shaft. You mentioned something not spinning around that the belt goes on....that would indicate the belt is broken and needs replacement. Unfortunately I have the same vacuum and have replaced the belt 2 times in a very short period of time. I think something is defective with it to need replacement so often.
J. Jernigan
December 2005