BMW E36 window stuck in open position

My passenger side window on my 1998 318is coupe has been stuck in the closed position for some time.

I can usually get it going by removing the door trim and then hitting the window motor with a mallet.

As it is summer and hot and my air conditioning also stopped working some time ago, I thought I would try and get the window working.

I got the window going with a hard hit and the next day on my way to work gave it a go. It moved three inches and then stopped. No amount of hitting would get it going again.

I was forced to leave my car at work in a carpark with the window down and nothing but a piece of cardboard to protect it. Fortunately there was no rain.
What can you do if your window gets stuck open?
The following procedure works for later model E36's but does require suitable tools.
Step 1
Remove the door trim. If you have owned an E36 for any length of time you should know how to do this.
Step 2
Disconnect the two cables that go to the window motor.
Step 3
The outer motor casing is held on with four Torx screws. The front two are easy to get out. The back two are a little harder. I found for one I could use a Torx socket with a universal joint and an extension bar. One of the others I had to use a small Torx tool I have (see picture). Some flat screwdrivers will fit these screws so you may be able to use one of those.
Step 4
Once you have the outer motor casing off (which takes a bit of wrangling) you can turn the motor and make the window go up. It takes many turns to make the window move a little. You will need to figure out which way to turn it to go up because I can't remember.

At some point your motor might free up like mine did. It's worth continuing turning to free it up fully. At some point you can put the motor back together again and give it a go. It may work. Mine did.

Most likely this problem is caused by a lack of lubrication somewhere, probably in the mechanism that turns the motors output 90 degrees to drive the window regulator mechanism. Unfortunately access to this may require you to remove the regulator.

When I put mine back together I left out the hardest to access of the screws in case I need to do emergency roadside repairs with limited tools.

Update
I foolishly tried using the window the following day. It got stuck again of course. I had to wind the motor to the top again. I noticed that as I wound it up (clockwise, by the way) there were several sections where it was difficult to turn and then there was a clunk and then easy to turn again. Something's jamming but I don't know what. I have disconnected the window switch for the moment.