This can be a bit of a bear, but you can do it with a long needle nose plier. After you get the old cover out of the way, go down on the shaft and push inon the detent release (middle of the shifter). You will note this shaft moves things just above the fork in the shifter. There is a small roll pin which you need to remove. Now the push button on the shaft comes out. The outside of the knob can now be removed by pulling up on it. Try to find this one in a manual.

Good luck!!

dick