2004 GMC Sierra 1500 Pickup Owner's Manual - Page 23

3. Pick up the latch plate and pull the belt across you. Don't let it get twisted. The shoulder belt may lock if you pull the belt across you very quickly. If this happens, let the belt go back slightly to unlock it. Then pull the belt across you more slowly. 4. Push the latch plate into the buckle until it clicks. Pull up on the latch plate to make sure it is secure. If the belt isn't long enough, see Safety Belt Extender on page 1-32. Make sure the release button on the buckle is positioned so you would be able to unbuckle the safety belt quickly if you ever had to. 1-17