Got it, I just wasn't sure about that allen head bolt. And the sprocket nut is 32mm. Parts are off, just waiting on FedEx to bring my new sprockets and chain. The sprocket nut was tight, but not as tight as I thought it would be. Cheater bar worked fine.Remove the allen head, then you can remove the nut. I am not sure the size but 32 sounds about right. The nut is on tight and I used a impact gun on mine. I put a broom handle through the back wheel resting on the swing arm on both sides to keep the wheel from turning.
I have used a torch in the past to heat the nut a bit if no impact gun, It will loosen the thread locker. Good idea to put Locktight when putting on the new one
You will need to screw the chain adjusters all the way in to remove the chain from the sprocket. The tricky part is putting the clutch cover back on, make sure you get the spacer in correctly and tighten slowly .