Open the cabinet just above the microwave and remove the power cord from the wall outlet.
Ask your helper to hold the microwave from the bottom to provide stability.
Unscrew each of the screws from the bottom of the cabinet. These screws extend through the cabinet into screw holes in the top of the microwave.
Set the screws aside. At this point your helper is holding the front of the microwave but is not bearing the full weight of the appliance because it is still secured to the wall mount.
Ask your helper to slightly tilt the microwave forward.
Press upward on the back left of the microwave. As you press upward, the wall mount tab should become removed from the hole on the microwave's back panel. Press upward on the back right side to free the microwave from the wall mount on that side as well. Keep both hands under the microwave to provide stability.
Lower the microwave to a stable, flat surface.