How do I replace the oven light bulbs?

Turn off power at the main power supply (fuse or breaker box). Unscrew the lens and remove it, then pull straight out on the light bulb to remove it from the socket. Replace with a new 12V - 20W halogen bulb, avoiding pressing the bulb with your fingers as oils from hands can damage it when hot. Screw the lens back on and turn power back on.