How do you change tail lights on 1998 Buick Park Avenue?

Open trunk lid inside there will be 5 or 6 large plastic thumb screws remove them and either 1/2 or the whole assy will come out,you'll have to remove wires on assy to replace lamps

If they're the ones in the trunk lid, you'll have to remove the carpet/plastic piece covering it, then remove all the small 10mm nuts holding the panel on. If they're the ones on the outside, you need to remove the cargo net holder and the phillips head screws on the plastic panel and pop off the panel. Then there will be about four 10mm nuts holding the stop/tail/turn assembly in place.