Unplug the microwave
Remove the turntable and roller ring
Wash the turntable and roller ring with warm soapy water
Wipe the interior with a damp cloth or sponge
Clean stubborn spots with a mixture of water and vinegar
Wipe the ceiling, walls, floor, and door interior
Clean the door seal and edges carefully
Wipe the control panel with a lightly damp cloth
Dry all surfaces with a clean towel
Reassemble the turntable and roller ring
Plug the microwave back in