Anyone ever disassemble a distributor - need help

I have the plate removed. I’m trying to access the springs to swap them out. Ends of both springs nearest the center shaft are not accessible due to the slotted mechanism hiding them. I believe the shaft will need to be removed. What’s the best way to remove the shaft ? Does the top rotor nut twist off ? Or do I need to knock out the dowel pin penetrating the plastic bushing ? I want to avoid messing with the dowel pin if I can. As I don’t want to risk it ever falling out.