2003 Buick Regal Owner's Manual - Page 260
2003 Buick Regal Manual
Page 260 highlights
Taillamps, Turn Signal, and Stsplamps I 3. Remove the three plastic wing nuts (A). There is one wing nut located on the outside of the carpet. The other two are located underneath the carpet. 4. Pull the taillamp housing (B) away from the body of the vehicle. A A 5. Squeeze the tab on the socket and turn the socket counterclockwise. 6. Pull out the socket. B 7. Pull the old bulb out of the socket. (There are two bulbs on each taillamp.) 8. Push in a new bulb. 9. Reverse these steps to reinstall the lamp assembly 1. Open the trunk. 2. If your vehicle is equipped with a convenience net, remove it. 5-55