FWIW, i recently replaced mine because the knob body cracked and wouldn't stay on. You can probably find a stock shift knob at autozone. Thats where I got mine. (1988 Olds Delta8
If yours has a plastic body like mine, I would try squeezing it with vice grips to crack the knob body, rather than pulling it off.
Mine was made of plastic and it cracked, so I think with a little effort you shuld be able to crack it and it should slide off easily. Of course, you will have to buy a new one, but mine was only $4.99.
Hope this helps. Good luck.
jasper