Pontiac 1997 Grand Prix Owner's Manual page 311

5. Remove the bulb from the socket.
6. Place the new bulb into the socket.
7. Turn the bulb socket 114 turn clockwise to replace it.
8. Carefully replace the headlamp assembly into the
vehicle. Be careful to avoid scratching or chipping
the paint on the vehicle while replacing.
9. Replace the two bolts on the top of the
headlamp assembly.
10. Close the hood.
Center High-Mounted Stoplamp
1. Open the trunk.
2. Reach through the access opening in the trunk and
remove the slotted vent by squeezing the ends and
pulling down.