Clutch basket big nut

[Chrome Megaphone]

I bought a GPZ900 Clyner manual thinking it would be the same except for the final drive but found out differently.  I'm trying to split the cases and upon removal of clutch cover discovered the C10 clutch has this machined part assembly that spins freely with the nut even with the trans in gear and a long extension through the connecting rods.  I ordered a clutch vice grip tool but it is still in the mail.  How am I supposed to hold the center still with that, there are grooves but they look pretty shallow.  Anyone here ever do this job before?  Thanks in advance.

[Chrome Megaphone]

The GPZ manual

[Chrome Megaphone]

Well I had put the inner splined hub in a box and forgot!  Anyhow the USPS misrouted my clutch vice grip tool and I got impatient so did this.  Second time now I used cord wrapped tightly and it worked fine for removal.  Was concerned about bending a bolt, or worse cracking the case, but the distribution of stress seems to do the job.

[Boomer]

Ingenious. 
When I had to remove mine I did it with the engine in the frame, bike in gear and a piece of 2x4 through the rear wheel resting on the swingarm.
I also drove the hammered in part back out a bit since I was replacing the nut anyway.
--Edit--
Just checked your pics and that is not a C10 clutch. Just about everything looks different to those in the manual and those I've worked on.

[kkja13]

I like it megaphone!
Where there's a will, there's a way...when the mail is too slow...or especially when the dollars are scarce (my case).

[Summit670]

I agree, very creative indeed. 

I used a 1/2” air impact to remove and install.   For rough torque on install, I but a large bolt in a vice and tried each of the 4 settings on my impact to find one that was close.   I used a torque wrench on the bench bolt to verify how close the impact setting was. 

In retrospect, I could have also played with the air pressure to get even closer.