When you go into the dealer to buy the new belt (don't try to rig it, you will be replacing it again very soon if you do), ask them how to replace it. If they are a decent dealer they will have no qualms in helping you out. Unfortunately you bought a residential mower and it will probably not last long when used commercially (I would bet you will be replacing the drivetrain and wheels before long).

The guards are usually held in place by one or two 3/8" screws and not hard to remove. You may need to remove the blade and then reinstall and turn the blade to get the belt onto the pulley. Disconnect the spark plug first and always have the gas tank half empty and in the upward position when you turn the mower on its side.

Thanks Baymee and Metal.

For anyone needing some help replacing the Toro Personal Pace belt the attached link should help. Although I found it impossible to slip the belt between the rear pulley bracket and the pulley even with the front belt guard removed. Instead, I removed the wheels and the spring attached to the pulley bracket, turned the axle, removed the pulley bracket, replaced the belt and put everything back together. Took some doing but it works fine.

Here is a link that might be useful: Toro Personal Pace Belt Replacement

Great link, but here's one more question, does anybody know the belt measurements for the Toro 20332, p/n 115-4669, I know it 3/8 wide, but not sure of the length, can't find anything on the web, even called my local mower shop & they didn't have a cross for it. Thanks