I had a very reputable shop put new carpet in my 69 Firebird TH400. I figured they would do a better job than I could. Carpet looks great but now the car won't come out of park unless I manhandle it. I don't think there button on the top of the shifter knob is depressing properly. Any one solve such a problem before? Can anyone tell me how to get the shifter knob off and reinstall it? Thanks!