Press the lock switch located under the trunk lid trim (tailgate), and lift the lid (door) up.
NOTE: This is the location of the tailgate lock switch. The trunk lid is held open by torsion bars.
To close the lid (door), press on the top panel of the lid (door) and slam it until the lock engages.
NOTE: The trunk lid lock switch also functions when the ignition is off. If the keys are accidentally locked in the trunk and the electric lock drive does not work (for example, when the battery is disconnected) the trunk lid lock can be unlocked in an emergency. To do this, fold the rear seat back forward (see "Back seat")...
...and, having gained access to the trunk through the opened opening, turn the emergency release lever of the lock counterclockwise until it stops using the opening in the rear trim of the trunk with the square key "8". Grasp the upper edge of the niche for the license plate and lift the cover up.
[Information taken from the official website CHEVYMAN]