Cadillac 1999 Seville Owner's Manual page 304

Center High-Mounted Stoplamp (CHMSL)
The individual bulbs in the CHMSL are not serviceable.
See your dealer for assistance.
Rear Turn Signal Lamps and Taillamps
1. Open the trunk to gain access to the lamp housing.
3. Move the spare tire cover out of the way.
4. Pull the trunk trim away to access the wing nuts.
6-40
2. Remove the rear
compartment sill plate
by removing the upper
convenience net
retainers, located at
each end, as shown.
5. Remove the three wing nuts that fasten the taillamp
to the body.
6. Gently remove the taillamp from the body. The
taillamp is on the bottom of the housing and the rear
turn signal lamp is on the upper part of the housing.
yellowblue