how do i change back signal light bulb

First pull trunk carpet away from below the trunk opening edge behind brake lamp assembly inside trunk. Unscrew the three black plastic retaining nuts holding the brake lamp assembly, and unplug the wire harness connection. (there is a locking tab on this connector that must be released before it will disconnect) Now push the three threaded bolts exposed, while teasing the brake lamp assembly from the vehicle. The individual lampsockets will be exposed, turn the desired socket 90 degrees to release, and replace the bulb by pulling outward. Reverse these steps to reinstall.

How do you release the tab that you speak of for removing the tail light?