Open the cabinets above the Frigidaire microwave and remove anything stored there.
Locate the cord from the microwave inside the cabinet. Follow the cord with your hands to the socket. Grasp the plug firmly and pull it out.
Check for vent ducting connected to the Frigidaire microwave. This may not be present in all models. Remove any straps or bands holding the ducting in place, using the the scissors or snips. Pull the ducting out of the top of the oven where it connects.
Have an assistant brace the oven from below. Locate the screws in the bottom of the cabinet holding the microwave oven in place. Loosen these, one at a time with a screwdriver or power drill and screwdriver bit.
Have your assistant slowly lower the front of the Frigidaire to about a 45-degree angle. Feed the cord through the bottom of the cabinet and onto the top of the oven.
Check for clips or screws holding the Frigidaire in place on the wall rack. Remove any screws with the screwdriver.
Pull the oven forward and off the bottom brackets.