How to change a tire on a buick Lesabre?

Im not sure, but sometimes GM put a removable decorative center cap over the center of the wheel that you may need to remove. Try this; Look at the center of the wheel, do you see a round cover? Perhaps with the design of a 3 stacked shields? (That was a buick symbol back in the day)If so, look to see if you can get a flat head screw drive behind it to pry it off. If so, once exposed, you should see a fastener (bolt or screw) that requires a special tool to get it off. Chances are the tool is long gone due to the age of the car. If you were to have it, it would be located in a small envelope in the glove compartment or attached to the lug wrench. If not, you generally can use a pair of needle nose pliers to fabricate a sort of make shift tool to get the cover off with. Once off, you should see the exposed lug nuts and you should be good to go.