You have to use a Dremel tool with cutoff wheels and cut from under the primary. You cut opposite of the split where the pinch bolt goes through. Its got to be cut at least 1/2 way around the circumference of the shift shaft. You end up cutting the bottom of the old shift lever off and then just remove the rest.
I have never done it but there is a video on his site. I think its easier to pull the primary IMO.
Cutting it with a wheel is the procedure they recommend. I agree that just removing the primary is easier. But going back on with one of these simplifies things in the future if it happens again!!
TQ