1993 Buick Roadmaster Owner's Manual - Page 228

O r , the equipmentfor the wagon is in the rear storage compartment... a To access the equipmentin your wagon, turn the slotted release button located on the rear,edge of thk cover. Rempve thecovef by pulliing,it away fkom the window and then sliding toward the rear, it Ming it up and out of thelower track. The wagon tire changing equipmen1 can now be removed.