Unplug your GE Profile microwave from the wall outlet. If you cannot access the plug, turn off the breaker inside the panel box that supplies electricity to your microwave.
Unscrew and remove the two screws holding the exhaust grill to the oven above the GE Profile microwave door. Remove the exhaust grill from the top of the microwave.
Reach inside the grill opening and remove the two screws holding the cover lamp to the microwave. Lift the cover lamp to expose the halogen bulb.
Pull the bulb from the cover lamp. Take the halogen bulb with you to a home improvement store to purchase the correct replacement bulb.
Wrap the replacement halogen bulb in tissue. Touching the halogen bulb with your fingers leaves skin oils on the glass and can damage the bulb. Insert the bulb into the cover lamp.
Replace the cover lamp and attach it with the two screws you removed in Step 3.
Reattach the exhaust grill to the front of the microwave with the two screws you removed in Step 2. Plug the microwave into the wall or turn the breaker on inside the panel box.