I have written about the dangers of power window removal many times over the years. But, since we have new, younger members inquiring, here we go. If this is old info, move on.
The spring that is part of the window scissors, is super powerful and can hurt you!
Ask how I know!
First, if you want to remove the motor, you can do it without removing the scissors mech.
Two of the bolts holding the motor on are visible. The third is behind the door inner frame.
Simply use a hole saw to drill a hole over the third bolt and you can remove the motor, easily.
Doing it this way, there is no problem with the scissor lift. It just sits there.
Work on the motor and reinstall it, it is not indexed.
Now, if you must remove the whole scissor assembly, here's where you must be careful.
Note that the spring is there to counterbalance the weight of the glass.
Lower the assembly, to remove the two bolts holding the glass to it. Remove the glass from the door. You can take a 2X4 and put in the door under the glass to hold it up, if youy wish.
Then you can remove the lift assembly, with the motor still attached.
Once out. DO THIS BEFORE TAKING THE MOTOR LOOSE! The motor keeps the spring from unloading, explosively! After I ended up with a dent in my forehead, I started to do this!
Drill a hole through one arm and the lift frame and bolt them together. Avoid using Vice Grips to hold the arm as they can let go and the arm will fly. Drill the hole and bolt it, your body parts will stay intact.
The hole in the door inner frame for the motor bolt removal and the bolt through the arm are not factory, but no one will see them and wouldn't know anyway.
Hope this helps to prevent pain and suffering, Ray