I take it you want to put a cover on it? It will be tough to prise off as its new etc. I'd suggest grasping the mount with one hand and with the other hand hold the mirror the opposite side pulling it towards yourself so that the side closest to your hand holding the mount touches it and then carry on pulling the one side of the mirror towards yourself prising it off the mount. This way you shouldn't accidentally pull the mount off the glass. My thoughts are that you will have to prise it quite firmly against the hand holding the mount. Hope this helps. And doesn't sound patronising in my instructions as I didn't know any other way to explain haha!