It all depends on what type of rim you have but whatever you DO NOT use power Sawzall (as suggested) or skill saw or Hedge trimmer. If its the older softer brown wholegrain trim which is actually single pieces on each side you need lots and lots of patience, a long 4" retractable razor knife and a putty knife to pull the trim away from the glass as you slowly but surly cut, cut,cut the silicone away that is is holding it in place. Pull to hard and the trim will snap and not be available for later use. Its all silicone and only silicone holding the trim, sometimes its easy becasue not much silicone was used and sometimes it take allot of exercise to get it all cut. If you are using the blade correctly you will not cut the glass or your hand. Do it wrong and forcefully and you will chip glass and the blade will slip and cut your hand or thumb artery severely bleeding. Be careful, deliberate, and methodical always cutting between the silicone and glass in long and short swipes away from your body and never-ever toward your body. Eventually the plastic pieces will start to give way and come off.
The other type trim is the newer injected molded one piece hard plastic trim. The 4 corners on this trim can be cut with a small drummer cutting wheel or a hot knife electric or heating a wooden handle knife on the stove burner and melt-cutting each corner to make 4 separate pieces. Now you are ready to use the same method above for removing the trim by removing the silicon holding it in place. You can also use a heat blower which looks like a hair dryer only 300% hotter and it will soften the hard plastic molded frame so that it can be bent away from the glass to more easily cut the silicone. This plastic can be damaged becasue you cant use it again.
Again if your scratching the glass with the razor, you not handling the razor correctly and with control. Remember you make long deliberate cuts like cutting a pizza over and over until it gives way, you don't stab at it with your steely knife cause you just wont kill the beast.
