Chevrolet 2007 HH7 Owner's Manual page 108

The lever is located about three inches
(7.62 cm) behind the trim in the access hole.
3. Insert a tool into the access hole.
108
2. Locate the release
lever on the latch.
4. The liftgate will unlatch when the lever is
pushed rearward. Push the liftgate to open.
5. Reinstall the trim plug.
Push the release lever
rearward.