Pontiac 1999 Firebird Owner's Manual page 291

Rear Sidemarker
Replacing a rear sidemarker bulb:
1. Remove the screw from the sidemarker assembly.
2. To pull out the bulb housing, tilt the housing to
remove the end with the tab.
3. Turn the bulb and socket counterclockwise and
gently pull out.
4. Reverse the steps with a new bulb.
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