1999 GMC Sonoma Owner's Manual - Page 224

yellowblue CAUTION: Changing a tire can cause an injury. The vehicle can slip off the jack and roll over you or other people. You and they could be badly injured. Find a level place to change your tire. To help prevent the vehicle from moving: 1. Set the parking brake firmly. 2. Put an automatic transmission shift lever in PARK (P) or shift a manual transmission to FIRST (1) or REVERSE (R). 3. Turn off the engine. 4. Put the wheel blocks at the front and rear of the tire farthest away from the one being changed. That would be the tire on the other side of the vehicle, at the opposite end. The following steps will tell you how to use the jack and change a tire. Removing the Spare Tire and Tools The jacking equipment you'll need is stored inside the plastic jack cover which is behind the front seats, either on the center of the wall (extended cab) or on the passenger's side of the wall (regular cab). 5-20