I have removed a couple of these.

Your going to need one of those long stanley knives and alot of patience and never try to force the glass on the edges.

Cut off the outer rubber as much as you can.

Then from inside keep running the knife from the centre to each corner at the same time applying GENTLE outwards pressure then down each side and finally around the bottom.

The bottom has hard plastic cup things which you're better off cutting off as these are what usually crack the glass

Its also alot easier if the dashboard is out of the car as well