regalchef

I recently purchased a new gps antenna and am looking to put it on the back window. The problem is the old one is still on there and the wiring is under the molding. I hear it is impossible to take off the molding without damaging the glass and for that matter can I even get the sharkfin off the glass to apply the new one. Is this something I need to bring to MB to have done or would a reputable glass place be able to do it??