GMC 1995 Suburban Owner's Manual page 59

Shoulder Belt Height Adjuster (4-DOOr Utility Models)
Move the shoulder belt adjuster to the height that is right for
you.
To move it down, push in at the word PRESS and move the height adjuster
to the desired position. You can move the adjuster up just by pushing up on
the shoulder belt guide. After you move the adjuster to where you want it,
try to move it down without pushing in to make sure it has locked into
position.
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 unlatch the belt,
just push the button
the buckle.
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