How hard is it to change window motor on 2003 trail blazer

It's not that hard but there are parts that always break. Most dealers will call in a windshield repair shop to do this job since there more experience then the Dealer shop there self. You can have like Apple Auto Glass or Speedy Auto Glass to do the job for you which there shop rate is less then the Dealers since they will mark up the repair. But if you must remove the inside door panel to gain access to the electric motor and the window needs to be in the up position. If it's in the down position you need to disconnect the window from the window tracks and tape it up out of the way so you can get to the electric motor, Once you can get access to the electric motor, disconnect the wire harness and unbolt the motor from the door. To remove the electric motor with the track will take a few try's, it needs to wiggle out through limited space between the door frame's and then you can replace the electric motor from the track and everything goes back in revers the same way your removed and replace any clips that may have gotten damaged. Good luck and hope this helps.