Re: Removal and installation of a shift knob on 850R (T5Rfanatanic)
I've replaced mine twice. On the S70, anyway, the procedure is - yank as hard as you can to get the thing off. It's not easy and it may take a few really good pulls, but it will come off. To put it on - a rubber mallet is useful for force without too much risk of damage - but you should cover the shift knob with some sort of thick padding so the mallet won't leave marks or damage it.
Before removing the old one - I'd suggest marking where it's bottom is on the shift stalk (a piece of masking tape or a felt tip marker would work), because you have to make sure that the new one is down as far as it can go, otherwise the shift button will not engage and the knob won't work correctly. Even if it's a millimeter, or two, from being fully on, you can still have it not work, even though the installation looks good.