how can i fix electric window mechanism, vauxhall astra?

This is not an easy job but I can tell you as far as I know.
remove the door panel flip the screw hole retaining caps out the handle and the storage container and about 4 under the bottom of the door.
Feed the elec window switch through the gap in the panel and remove the panel by lifting up to release it from the top of the door. Peel back the plastic membrane, watch the pitch sealant around the edges, the blacks stuff. You will probably find the control arm has broken away from the drive plate It's not repairable it has to be replaced. If the motor [assuming it's electric] is riveted to the door then this will have to be drilled out then re-riveted or bolted with short bolts so they miss the mechanism when operated. Can't say from here on as I never completed the job and my pal has gone to Aus'y
It is a pig of a job that's why he got it in the end. I suggest you get a price off a garage.

bob
January 2005