Remove the door handle bezel by inserting a flat trim removal tool between the door panel and handle bezel to release the locking tabs.
How to remove rear door glass on a chevy tracker.
By removing the motor if applicable and unbolting the regulator from the door it can be removed.
Remove the door panel push pins and trim screws.
Remove all door panel electrical connectors.
This a video showing how to replace the rear door glass on your own instead of going to a shop.
Some models will have tightener bolts on each side to prevent the glass from moving and these will need to be removed also.
Sorry for the video was bad but i made a quick one of how to do it since i could really find it myself so i had to do it on my own hopefully this helps someo.