1997 Buick Century Owner's Manual - Page 252

... Removing the Spare Tire and Tools The equipment you'll need is in the trunk. Pull the carpeted mat up from the floor of the trunk. (See "Compact Spare Tire" later in this section for more information about the compact spare.) 1. Turn the center nut on the compact spare cover to the left to remove it. Then lift and remove the cover. The followingsteps will tell you how to use the jack and change a tire. 5-26