The number plate light bulbs on your Toyota Camry are usually the last light bulbs you think about. Hopefully, it wasn't a police officer pulling your over to inform you that one or both were out. Replacing them isn't too difficult, but it will require taking some stuff apart to get to them. If you want to save some money on labour charges, the replacement bulbs are relatively inexpensive, so you might as well learn how to pop them in yourself.
Open the boot to the Toyota Camry. Remove the interior boot liner from the back of the vehicle. Use a Phillips screwdriver to twist the small centre screw from the middle of the plastic fastener. The screw will come up about 1/4 of an inch and then you can pry the entire fastener/plug from the predrilled hole. Remove enough fasteners to allow you to get to the number plate light assembly.
Turn the number plate light socket counterclockwise about a quarter turn to release it. They may be tight, but this is how they come out.
Extract the socket from the assembly and simply pull the light bulb from the socket.
Insert the new bulb into the socket.
Turn the lights on and check to make sure the bulb is working properly.
Insert the socket back into the assembly and turn a quarter turn clockwise until locked into place.
Reinsert the plug fasteners in the liner. Push them into the predrilled holes and push down onto the plastic screw.
Remove the screwdrivers and close the boot.