Hello Rich, the top of the shaft is splined, so the knob will pull off with some force, some people use a rubber mallet and gently tap underneath, perhaps using a spanner or grips open larger than the shaft, and some padding. I would be slightly concerned about damaging the bottom bush and linkage if you pull or tap too vigorously, so might be better supporting the shaft somehow, with padded grips, or taking it off the car first. Replacing the knob is the opposite, line the knob up first accurately before you tap it on, you don't want to have to rotate it, as that will just loosen it up again