Ovens with glass doors and an inside light are a nice convenience. The light switch allows you to check on cooking food without opening the door and disturbing the heat distribution. When the light bulb burns out you will need to replace the bulb. Regular incandescent or halogen bulbs will not work in an oven. These types of bulbs cannot withstand oven temperature and will meld to the socket. Purchase replacement oven rated light bulbs from the hardware store.
Unplug the oven from the wall socket. Open the oven door and locate the oven bulb cover. Usually the oven light will be on the right rear of the oven.
Hold the oven bulb cover with one hand. There is a wire bail that secures the bulb cover to the oven. Pull the wire bail off of the bulb cover with your free hand. Carefully remove the bulb cover and set it down somewhere where the cover will not get broken.
Unscrew the defective oven bulb with your fingers counterclockwise. Throw the defective bulb in the trash. Insert the new oven bulb into the socket and turn the bulb clockwise to tighten the bulb to the socket.
Place the oven bulb cover over the light bulb until the cover meets flush with the rear of the oven. Hold the cover with one hand while sliding the wire bail over the cover to secure the cover to the bulb fixture.
Close the oven door and plug the oven back into the wall outlet.
Use only appliance rated replacement bulbs in an oven. If you do not have a light cover now would be a good time to purchase one. Light covers protect the oven in the event an oven bulb breaks during operation.
Always disconnect power from appliances before attempting repairs.