Take the door trim off - see
hereThe window channel is fixed by four bolts - a 13mm on the outside edge at the top, a torx on the inside edge at the top and two 10mm's on the inside of the window channel at the bottom inside of the door either side. Unplug the mirror, you don't need to take it off if you don't want to.
Drop the window or what's left of it to about halfway down the door so the channel will slide inside the door on the runners, the window needs to be dropped enough so you can slide it one way off one runner, tip it at an angle and slide the other way off the other runner - then just lift out. Fitting is the opposite of removal as they say.