We lost another driver side mirror being parked on our insane street. This time the whole glass and backing came off cleanly. The manual adjuster mechanism is intact. I have another complete mirror assembly but it is power and the broken one is manual. How can I get the mirror glass part off of the power and put it on the manual? I know it has to be possible because they sell just the mirror and backing so that you can replace a broken glass. But how does the old glass release from the adjuster mechanism?