Open the door underneath the sink and look for the garbage disposal button. The button typically is slightly recessed and may be directly underneath the sink or to the side.
Press the recessed button so that it goes all the way in. Go back to the fuse box and turn on the electricity to the garbage disposal.
Run water and turn the disposal back on to see if it works. Listen for humming, which indicates that the disposal is jammed. No sound means that you may have blown a fuse and power is no longer getting to the disposal. Turn the power back off at the fuse box.
Reach under the disposer with an 1/4-inch Allen wrench to manually crank the blade to fix the jam. Place the wrench in the center of the bottom of the disposal unit.
Turn the wrench counterclockwise to break up the jam. Use tongs to remove whatever is causing the jam from the disposal.
Turn the power back on to the disposal.