Answer
First you will need to determine if the assembly can be removed or if you can just replace the bulb. if it is embedded, then look behind the bumper and there should be a bulb housing. usually they rotate to facilitate replacing the bulb, or you might have to remove the assembly itself. once you have it out, it should be easy to replace the bulb. do not touch the bulb with your fingers as the oil from your hands can damage it. wear gloves to handle the new bulb.