I want to take off the shift knob of my 1995g20 van and put on a cue ball,can't get the shift knob to budge, any good way to take it off? Does it come off?

I drove the pin out, clamped in a vise, cut off with a sawzall and got my tap and die set out!

It would help us to see a picture to be sure just what you've got, but provided it isn't molded in place, it had to screw or press on. If it's threaded. they may have used a threadlock type adhesive like Loctite or a contact cement on any threads. Perhaps try cautiously heating it at it's base with a hot air gun, then use a moist rag or leather gloves for a better grip, and try turning it then while it's warmed up..

Like "mythreesons" said drive pin out at shaft base on column if you need to put it in vise and the knob is just pushed on with adhesive so you will have to thread it or make the ball a tight pressed fit.