BCS 715 Clutch is stuck

[coaster]

I have a 715 with a stuck clutch. I've removed the engine, but I think to remove the clutch the hex nut is on the side of the clutch versus inside the clutch/down the shaft. That hex nut appears to be stuck, but it's surrounded by a regular standard nut. Just a question: am I supposed to remove the standard nut surrounding the hex or just the hex? I just want to be sure before I go applying pressure to the wrong thing. Attached are some pics for info. I think the hex bolt that I should loosen is shown in the red square in the first pic.

 

[coaster]

Seems that this should be in the 2-wheel tractor section, so I created a post there. Consider this one dead.