1. Turn the ignition to the "ON" position, but do not start the engine.
2. Press and hold the "UNLOCK" button on the driver's door for at least 5 seconds.
3. The automatic door locking feature will be disabled.
4. To enable the automatic door locking feature again, simply repeat steps 1 and 2.
Note: On some Trailblazer models, you may need to press and hold the "UNLOCK" button for up to 10 seconds to disable the automatic door locking feature.