Replacing power door lock latch motor

Hi,
Both of the power door lock latch motors on the two rear doors of my 2000 LHS are making some loud squealing noise when they lock the doors. That always makes me jump when the doors lock at the speed 15mph. That happened to the driver side door years ago, but was replaced under warranty. Now, the car is at 118K miles, I want to replace it myself.
Any experts out there can give me some pointers? I have a repair manual for that car. I got the trim panel out and got to the point where it said "remove the rear glass rail", just that one sentence. That got me stuck. The instruction said to close the window, with that I can't see how that rear glass rail can be removed. I then lower the glass, but it is still not quite possible. Without removing that rail, the power lock motor cannot come out.
Any help is appreciated. Thanks.

Norbe

No idea how to replace it but my local car audio and alarm place will do it for $35.00 per door and that includes the actuator. If there is a place by you, call and ask them what the cost to replace the doorlock actuator in whichever door you need. If you say it like that they will know you know what you are talking about. For $35.00 to not have to get the door panel off and have to mess with anything, it's well worth it.