This is a fairly common problem. Most homeowners either have or will face this at some point. This is a good video of how to fix the problem yourself. One thing I would add to his remedies is that most disposals come with a disposal wrench which looks like a big allen wrench (5 sided shaft with a 90 degree bend) and this can be inserted in the center at the bottom (from underneath) of many disposals to manually turn the disposal and free it. Of course, make sure the switch is off when you do this. If you see one of these wrenches laying in the bottom of your base cabinet, that’s what it’s for.
Kevin Hicks 