Completely disconnect the power flow from the garbage disposal by flipping the switch that controls this appliance in your breaker box.
Take a look down the drain by shining a flashlight and poking around with a pair of tongs or pliers.
Remove any visible debris that might be jamming the disposal.
Find the hole shaped like a hexagon that's located on the underside of the disposal underneath the sink.
Place a hex wrench into this hole and turn the wrench in a complete circle both clockwise and counter-clockwise.
Turn the breaker back on, turn on the faucet, and flip the switch to the disposal to see if it is working.