How do I remove rear door panel to repair power window? on 2002 Buick LeSabre

My left rear power window lift arm has jumped off track. The motor runs and I need to place the arm on the track but I do not know how to remove the panel on this model.

Asked by for the 2002 Buick LeSabre
Having recently repaired both rear window lifters on my 2002 LeSabre, I can tell you they do not have lift arms. The windows are clamped in a lifter which runs in a vertical track. The lifter is driven up and down by a cable on a drum, driven by the motor.
On both of mine the plastic holding the lift end of the cable broke, releasing the cable and dropping the window. I repaired mine. Removing the panel is not even a start on the job. The lifter is broken. Spare yourself have it replaced.