Rear view mirror trim replacement

If you have had experience with replacing the trim on a W163 rear view mirror, please post your insights here. I am trying to figure out how to remove the trim from the mirror without breaking it, and I've had no luck so far.

Below is a picture of the trim piece I am trying to remove.

The mirror in our ML broke and I asked the dealer to take a look at it. I had thought it was just dislodged. They broke it even more, and completely destroyed the trim. As a new mirror was quoted as $1800 (can you believe it!), I bought a used one off of eBay. It didn't have trim and, I did not realize that the trim is not available separately. I put the original broken trim up with double sided tape, but I've been searching eBay for a replacement mirror since. It is hard to find a tan auto dimming mirror with space for the rain sensor and intact trim for a reasonable price. So I finally found the pictured mirror (not auto dimming) for less than $30 on eBay. Now I am trying to figure out how to switch out the trim on this mirror to the mirror in the car.

Any help will be appreciated!