Buick 2005 LaCrosse Owner's Manual page 325

3. Remove the four plastic wing nuts retaining the
trunk trim. There are two wing nuts located on
the driver's side (shown) and two located on the
passenger's side of the vehicle.
4. Pull back the trunk trim.
5. Remove the two wing nuts holding the taillamp
assembly in place.
6. Pull out the taillamp assembly and disconnect the
wiring harness.
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