Twist off the lock-nut on the top of the disposal and the bottom of the drain pipe.
Wiggle the drain pipe so it loosens from inside the garbage disposal.
Insert a screwdriver into one of the metal flanges on the top of the disposal. Slowly unscrew the top clockwise. Because it is only a rubber gasket, be careful not to tear it by unscrewing it too fast. Once it is loosened, finish untightening the unit with your hand.
Pop off the Whirlaway garbage disposal from underneath the sink.
Disconnect the dishwasher drain line at the garbage disposal. If there isn't a dishwasher, then no line needs to disconnected.
Unbolt the electrical outlet from the bottom of the Whirlaway garbage disposal. Use a wrench to unscrew the nut.