If you have a manual you have to destroy the knob to get it off. I replaced mine with the Volvo leather knob about two years ago.
It took me about five minutes to whittle away the bottom of the knob(just above the plastic rim) to gain access and break the plastic cir-clip that holds the knob to the gear shift shaft. You may be able to break the clip with out whittling away the knob, get a big set of chanel-lock plyers and grab the base of the knob above the plastic rim (rim separating the knob from the boot) and squeeze as hard as possible (the idea is to crack an internal plastic ring). If it feels like you crushed something, then try pulling up. Installation of the new one is simple, pop it on (permanently).