Buick 1999 LeSabre Owner's Manual page 268

Headlamps
This procedure is for both the driver's and passenger's
side headlamps.
1. Use a 10 mm hex socket to remove two bolts
retaining the headlamp assembly.
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2. Slide the headlamp outboard until the pins are loose.
3. Remove the headlamp assembly to access the bulbs.
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