I pulled mine off with a huge set of mole grips made a right mess.
I found a better way to do it though
Found a minty alfa 145/6 that was in a scrapyard with a nice gearknob on it , leathery and gear ratio's were in right place on top of it. So tried pulling with my hands, no avail, tried twisting, no avail. Guy in yard lent me a huge open ended spanner and a lump hammer. Basically put the open end of spanner under the knob colllar and whack the spanner upwards with the lump hammer, took about 6or 8 hits and it just popped off.
Best bit was he gave me the knob for nothing, AND when I went to fit it to punto (took std one off ages ago, was just held on with gravity ) and just went straight on and sort of locked into place (cos if you twist it it damages the clicky hold on to the knob bit inside), and is still there!!!
Not sure if hitting upwards with a lump hammer will do the gearchange ball joint and linkages anygood, but then, who cares if the shift is a bit sloppy, makes it more fun doesn't it? LOL didn't do anydamage to alfas ball joint.