Locate the cooktop light cover, located on the underside of the microwave.
Remove the screw securing the cooktop light cover in place. Remove the light cover.
Unscrew the old light bulb and discard.
Screw the new light bulb into the light socket.
Replace the light cover. Secure it by replacing the screw that was originally removed.
Remove the two screws located on the vent grill at the top of the microwave. Depending on your model, it may be necessary to open the microwave door to access the screws.
Tilt the grill back. Pull it away to remove.
Open the light cover located behind the grill. The light cover may be secured with another screw or secured with a plastic or metal tab, depending on model.
Unscrew the old light bulb and discard.
Screw the new light bulb into the light socket.
Replace the light cover. Replace the grill and secure with the two screws that were originally removed.