My E82 135i drivers side (right, Aust.) broke and wound its way down by itself. Shouldn't have, but tried as you do to wind it back up and it made crunching noises.
Removed the door card / panel to find nothing strange (First time in a E82 door). Removed the motor and to find the cables in a mangled mess. Then after a bit of research I found that I probably made the mess when I tried to wind the window up..
I got a quote for a BMW replacement for the regulator $316 AU and $522 AU for a motor! Found a second hand regulator and motor for $165 which was savaged out by the wreckers breaking the T20 fasteners etc.. Then got quotes for installation from $110 AU (needed the car for 1 day from a smash repairs and $330 AU for pro window joint (need the car for 1/2 a day.
I with the help of a work mate decided to have a go ourselves knowing nothing about the install other than what little we could find on Youtube and 1addicts. Installed it this morning on our work shed and could not have gone better (tricky though) in one and a half hours or so. (door card already off)
After removing the door card which can be found on a couple of videos on Youtube. It will then be time to remove the glass. No videos on and E82/E88 removal of the glass. There was one who had removed the glass and fitted it on the floor to show you which was a bit helpful. As others have mentioned, the T20 bolts on the two fastening points cannot generally be removed from the inside of the door. Used multigrips from the outside side of the door and make sure you turn in a clockwise direction to loosen the two fasteners.
The triangle section inside the mirror needs removal and the inner door strip also needs to be removed. Be careful to work the strip from the front to the back and not bend it. Take note of the end at the top of the door which slots into the door and pops into three spots to lock it in. (I did not do this making it hard to re-install. Although we figured this out.)
We moved the window manually as my wire was broken and we could do so to about half way on the door and removed both of the fasteners from the window. The carefully removed the glass tilting from the back and up. Once removed we removed the old regulator from the car and placed the good parts from the old one (mounting points) which were savaged from the one bought from the wreckers. Be careful with the glass mount points and do not pull them back to hard as the plastic is brittle.
The good regulator and motor was then repositioned back into the door and fastened into place. 10mm nuts FYI. Three in the face of the door and two in the bottom back. There is also a holder in above the motor which needs to be removed and go back in.
We placed rags onto the inside door frame for re-installation of the glass as I just had ceramic tint put on! then carefully put the glass back in the reverse order of taking it out while my offsider guided the glass into the mounting points. We put the two glass retainer screws back in loosely using the T20 insert from the front so we could still maneuver the glass for adjustment. Reconnected the electric winder switch and followed the reset window procedure which someone on the forum nicely advised about. Move the window to the bottom and hold for 5 seconds (we did 6 or 7) and them moved it back to the top in small movements (not allowing the auto to engage). It was closed to right but had to adjust it with the door closed and open several times by moving the glass by hand. When we were happy we used multigrips to tighten the two fasteners fully. Counter clockwise to tighten.
We then re-installed the top weather strip which was tricky as did not pay enough attention when removed. Once back in properly the inner mirror section was placed back on and we checked the movement several times more ensuring the window was fully seated on the seal when the door was closed and moved the last 1/4 inches or so.
The door card / trim was re-fitted after checking all the 10mm nuts from the regulator were also tight.
Door is not back together and all is working sweet again. How long the second hand parts last is anybody's guess!! Might buy the genuine new one next time as I am sure there will probably be a next time.
We have never done this before. Two people with mechanical minds and no fear can get this job done with no problems so don't be afraid like I was.
I will do a video and upload to Youtube if it breaks again.
Good luck with giving this a go.