STuck piano hinge pin

My old project plane has working flap but it appears pin for hinge is
corroded and stuck.
Flap needs to be removed for access to rear main gear bracket.

I can't get a grip on holding the pin and pulling or twisting. Being cheap ,
would rather not cut the pin into small removable pieces as a long
replacement pin or piano hinge ships at a higher rate.

Suggestion would be appreciated, thanks. Dick