WARNING: This page is about a different car, the 2006 Mercury Montego, 2006 Ford Freestyle, and 2006 Ford Five Hundred. However, it is still accessible from the selected car via links, so may be relevant.
Fold the safety belt as indicated.
Fig 1: Folding Safety Belt
Courtesy of FORD MOTOR CO.
Pull the safety belt tongue over the fold in the safety belt.
Fig 2: Pulling Safety Belt Tongue Over Fold In Safety Belt