I just did my two front windows. It will take 45 minutes or so once you figure things out. The easiest way to remove the rivits is to just grind them out. An angle grinder makes quick work of them. A dremel could be used, but will take forever. You could also drill out the rivits if you have bits hard enough. Cheap bits will just spin there. You may also want to remove the metal bracket the door panel screws to. It makes getting to the rivit beneith it a lot easier to work around.
Once you remove the 5 rivits holding the regulator assembly, remove the two bolts holding the track to the inside of the door in place. This will allow you to "fold" up the mechanism and lower the window far enough to reach the two bolts holding the track to the bottom of the window.
Once the window is lose, raise it back up and support it in the up position. I used a rubber door stop wedged in the top. The regulator assembly can then be wrestled out.
Once out, there are 4 or 5 pop rivits that hold the motor to the spring loaded regulator assembly. Secure the assembly in a vice and drill out the rivets. These are softer alumnium rivets so they drill out easily. Be warned that the arm is under considerable tension from the spring and when the motor is removed will snap around. Secure the arm to something sturdy. My vice is large enough that I just "trapped" the arm in the jaws when I tightened it up arund the base.
The installation is pretty much the reverse. The motor should come with new bolts to mount to the regulator. You are on your own for the replacement bolts for the steel rivits in the door. I couldn't find any rivits large enough to hold the door in place so I just used small bolts. The bolts are a PITA to get in there, so I put the bolts in the assembly while it was out of the window and held them in place with a little bit of duct tape. Yeah it may look a little getto putting it in, but no one will likely ever see it again.