Step 13 - replacing the centrifugal clutch - remove the bolt

I saw the guide for replacing the clutch written by Sam Omiotek. I am at step 13 where it says to remove the bolt from the end of the crankshaft. But it doesn’t say how to hold the crankshaft. The bolt spins the crankshaft so there’s no torque available to remove the bolt. How do I keep the shaft from spinning while unscrewing the bolt? Help!

If you will email me directly I would much appreciate it. michael@bolincpa.com Or office phone 325-632-2011. Central time zone.