It may be down to cutting a hole in the door card?
Here are some pics that show about where the holes are, these pics are the drivers door, but it would mirror the passenger door. The hole to the upper left of these photos is where you need to get into.
https://picasaweb.
.com/hocrest1/Window#
Is your car grey? I have a door panel you can have for the cost of shipping. The Ecsaine may not be in the best shape, but if yours is better you can swap it over.