How do you change the rear turn signal light on a 91 Cadillac Coupe DeVille?

You need a T-15 star bit driver that is referred to as TORX. On the top and bottom of tail light are the screws. Carefully remove the chrome trim then the light pulls out after applying slight upward pressure. Once you twist out the socket the bulb simply unplugs. It should be either a 3057 or 3157 bulb. (i cant remember for sure)