Sticky clutch (motorcycle)

There was little moisture in the trans oil but the plates have rusted where the air was humid above the oil. The steel plates have bonded to the fiber plates.

2 options.

Start it, block it nose first against something solid like a tree or public library, strap the front wheel down if possible. Pull clutch lever, rev piss out of it, jam in to gear. This MAY break the plates loose. If so, ride it a bit, and you're golden.

Or

Remove kickstarter, pull clutch cover, remove (using one turn per screw at a time) the 5 or 6 bolts with clutch springs under 'em.
Pry the plates apart gently. If fiber sticks to the steels, replace 'em all (Prolly $60). If they pop apart clean, jam it back together, torque the screws IN STEPS to spec GENTLYYYY (The little aluminum studs that they thread into like to break off) with a QUALITY torque wrench (not Harbor Fright).
Replace gasket, re-install cover, replace lost oil and ride the piss out of it.