Feel or look straight-up at bottom for a slot in center into which a wrench can be inserted. 9 times out of 10 slot will be for hex wrench , aka Allen Wrench. Once wrench is in place, repeatedly rock motor clockwise then counter clockwise, increasing force each time until impeller moves.

Thank you both! I will give that all a try!

Garbage disposers ship with a wrench like this. But if you don't have one, you can use an Allen wrench as described above.

before allen wrenches we used broomsticks

still works

If this is to be continued kicked around, shouldn't someone find out what key the disposal is humming in? And btw, disposals come in various horsepowers,colors and brand names.