If you do not have a piston stop, Or you do not like applying too much pressure on the pison/rod. Then I suggest pinning a ratchet with a 14mm socket on the clutch nut against the left pedal on the ped. you will see what I mean when you get there.
these can stick like you would not believe, usually due to a bunch of dudes who have overtightened it while trying to remove it over the past 28 years.
you may need to use some penetrating oil, and/or butane torch to heat up the nut. I would avoid using an impact wrench if possible. One of my bikes starting knocking after taking the flywheel off using that method