Unplug the power cord from the electrical outlet. Remove the retaining screws from the grill on the front of the microwave and pull it away from the appliance.
Locate the light cover inside the grill area and remove the retaining screw with the Phillips screwdriver. Twist out the old light bulb and discard it.
Put on the cotton gloves and open the packaging for the new light bulb. Twist the new light bulb into the fixture. Replace the light bulb cover and tighten the retaining screw with a Phillips screwdriver.
Place the grill on the front of the microwave and install the retaining screws using a Phillips screwdriver. Plug the power cord into the electrical outlet and program the proper time into the microwave.