As Confucious say,"Man who go to bed with stiff problem...wake up with solution on hand!!
Here is the solution, a couple of long bolts with plenty of thread (or allthread bar). mate x 1.25mm
Screw them into the holes provided in the LH crankcase and turn evenly.
The end of the bolt will press on the flywheel, which is plenty strong enough to take the pressure.
As you are screwing, make sure the case comes up evenly and doesn't hang up on the output shaft.
Bolts screw down and push on crankshaft.

View of bolts poking through other side.

