I "inherited" my mother's Fellowes PS60-2. I plugged it in and put paper in the top opening. The green light came on and the sound of a motor was on but the teeth won't rotate in either direction. I know nothing about it other than it has a cord that you plug in,a switch for forward and reverse and a slot for paper to be chewed up. I don't even know how to remove the SQUARE HEADED SCREWS! What tool is used for the screws for removal and what should I be looking for inside the machine?
Please help. Thank you very much.

Office Equipment & Supplies - Fellowes - PS60C-2 Shredder