The Yank / Brute force method that is described in that thread, although works, isnt the best or easiest way to remove the gearknob.
You need to pull the knob button out from the top, which reveals a screw, which you undo to remove the back cover, to reveal a clip, which you remove, which allows you to remove the gearknob easily....
www.carmodder.com • Changing an Automatic Gear Knob for the Holden VE Commodore
Using the brute force method, all you are really doing is putting a lot of pressure on the clip, which hopefully pops off before it damages the silver plastic part of the gear knob.
I hope this helps...