Buick 2005 Century - Manual (Page 24)

To unlatch the belt, just push the button on the buckle.
The belt should go back out of the way.
Before you close the door, be sure the belt is out of
the way. If you slam the door on it, you can damage
both the belt and your vehicle.
Shoulder Belt Height Adjustment
Before you begin to drive, move the shoulder belt
adjuster to the height that is right for you.
Adjust the height so that the shoulder portion of the belt is
centered on your shoulder. The belt should be away from
your face and neck, but not falling off your shoulder.
To move it down, squeeze the release lever and the
shoulder belt guide as shown and move the height
adjuster to the desired position. You can move the
adjuster up just by pushing up on the shoulder belt guide.
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