My driver side electric window assembly collapsed and the window fell down inside the door. The motor is still very good, but I need info and/or a diagram of how it is assembled in order to repair it and get the needed parts. Can you help me with this problem?

The door trim is held on with a combination of screws and push clips Once you have the trim off you will probably find that the window motor regulator is defective. I would recommend replacing the regulator and motor as an assembly.

Are you sure of the year? Didn't think that they made a 1996 Buck rendezvous

.http://www.dormanproducts.com/gsearch.aspx?

first remove the door panel to give access to the window and regulator assembly you can move the window up or down in order to access the 2 screws or bolts holding the window to the regulatorr assembly if not possible put your hand up inside and try to loosen the screws or bolts with a wrench or small screw driver then the window should fall becareful not to break or damage the glass then unbolt the regulator from door frame and pull it out through the hole if electric the motor should come with it if just manual the rods and so on come with it if electric you need to unplug the motor connector

First check the fuses for both electric windows if they are good.The fuse box one is on the engine compartment driver side look for long retangular black box and open the fuse cover the cover should designate what the fuses and relay is for the other is on the driver side under the dashboard just above your left foot look under you should see another fuse box.If both fuses are good,then your going to have to check the window regulator which is inside each door.Open the door panel and check window regulator morethan likely the regulator assembly need to be change.You might just need the motor.The whole assembly is quite expensive.

Larry if the window does not go up or down its likely that the gear driven assembly or the motor on your electric window for the drivers door is bad. You will need to disassemble the door by removing the door panel to gain access to the electric motor. Hope this helps you will want to gain access to a service manual from a local parts store to help you with this venture. Good Luck

need to test and replace thewindow lift motor assembly

check to see if the window fell off the track,then check to see if the arm goes up and down when you push the button.

thw window either came off the window slider or the slider bracket, this can be determined by removing the door panel. this could also be cable driven and the cable has disconnected or broke, can also be determined by removing door panel.

Most all window motors and regulators are pop-riveted to the door. This requires special tools to reinstall the pop rivets and assembly.

Most likely the sound is coming from your "window lift assembly" being torn up. Your window motor attaches to the back of the assembly and winds up the cable that raises and lowers your window. Most likely the cable has come unattached and is grinding inside. 
You can buy a new assembly from Autozone (about $100 is what they usually run) and replace it. The first step is to remove the side panel from your door. Once the panel is off you can see where your motor is bolted on to the center of your door. Remove the motor and then unbolt the rest of the window lift assembly. Be careful though about removing the pins that attach your window to the lift assembly. Due to the curve of the glass, it only takes a little pressure to shatter the glass. Once the window lift assembly is replaced, put everything back the way it was before and you are good to go. 
It is not that complicated of a job, it just takes a little patience. Good luck!

If your power window motor is not moving up or down at all inside the door panel, you will need a new motor.
If your window is stuck and will not move, it is the motor - it is bad.
If your window falls down into the door panel, the window is off track.
Replacing a window motor is an easy fix, get another one from an auto parts store and replace it.
Good luck!