What Ace said... put a plastic bag over it and turn it upside down. You have to loosen one side to let the air in so the stuff will fall out. I always empty the stuff out of the teeth before I remove it so that paper doesn't fall on the floor. Also, don't fill it so full.
I think it's the last sentence that gets me. I don't know it's full until it stops. So then you have to take the top off, which leaves little pieces of shredded paper all over. I heard someone in a store shortly before Christmas telling someone else that since she shreds absolutely everything, she came up with the bright idea of using the shredded stuff as packing material when she sends Christmas packages. If someone used shredded paper as packing material in a box they sent me, I would track them down and kill them like a mad dog. Peanuts are bad enough.
I before E except when eight feisty neighbors seize a surfeit of weighty heifers.