Usually there is a small port in the bottom of the disposal on the bottom that you can get a allen wrench in. you can use that to turn the blade plate and free it up. take a shop vac and **** out the metal before you turn it back on. if that doesn't work alot of times you can get some dish soap and pour a ton down there and the soap will help flush the metal through the plates once they are freed up. but i would try and get them out first