The original rearview mirror in my 2006 DB9 looked like it had been through a repossession... The internal layers had delaminated and it looked, well, sad. I removed it by unscrewing the Torx screw that held it. It's a Donnelly 00708, which was conveniently used in the late 90s Volvos.

I bought a nice used one on ebay. The ball mount "pops" out with just a bit of force. This allowed me to swap my DB9 stalk for the volvo stalk. To install it I threw the mount into the freezer, and heated the mirror back with a heat gun. Not super hot, but just warm. Moderate force got the ball to pop into the mount. Well worth the 20 minutes and $20.00...