Sorry, I have never looked at one of those. If you have a good one (the passenger side) and a broken one (the drivers side), can you look at it and see how it is attached? Is there a screw missing or a broken plastic part or something? Maybe if you look at it real close, you can figure out how it goes together. I'm pretty sure you could get any broken or missing part from the PartsShop.
As far as I know, there are no service manuals available for the 2000 ML, except maybe on microfiche. And there always is startekinfo.com - $20 for 24 hours of browsing.