How do you remove the mounting tab from the rear view mirror on a ford pickup there is no set screw?

I encountered this problem myself and after an hour of messing around called the Ford Dealership to find out a probable solution. Basically, there is a clip behind the mounting plate itself that you must pry open to allow the mounting clip to release. There are no "specific" tools for doing this and best suggestion is to use a very small flat head screw driver to try and accomplish this feat. You must try and "twist" the clip to allow the for mounting plate to release from the mirror itself. Be careful as you could easily destroy the assembly piece if your pry too hard!

I encountered the same problem, after messing around for 45 minutes, I finally figured it out!

There is a small square slot at the end the set screw normally is. If you cut off a piece of coat hanger wire about 6 inches long and insert it in the square slot towards the center of the tab, it will release the spring clip holding it.

you then have both hands free to use a larger flat bladed screwdriver to gently pry the tab out!

Be careful though, it is all made of aluminum and is very fragile!