Turn off power to the microwave at the circuit breaker
Unplug the microwave if the plug is accessible
Remove the screw cover or trim plate, if present
Support the microwave with a helper
Locate and remove the mounting bolts from the upper cabinet
Tilt the front of the microwave slightly downward
Lift the microwave off the wall mounting plate or bracket
Disconnect the power cord completely, if not already unplugged
Lower the microwave carefully and set it aside
Remove the wall mounting bracket if needed
Patch or clean the wall and cabinet area if desired