Chevrolet 2007 Avalanche Owner's Manual page 108

6. Turn both glass lock knobs (D), located at
both top corners of the storage pocket, to
the locked position. Push in on the corner of
the rear glass to allow the lock knob to
engage more easily.
108
Once both glass lock knobs are in the locked
position, the rear glass is securely stored.
7. Push both latch levers up to the locked
position. You should hear a click when
each latch lever locks correctly.
The rear seats can be returned to the normal
position when the rear glass is out and
stored properly in the storage pocket.