Keep the ram mostly retracted. With the shaft opening on the bolt pointed down give the bolt a tap against a solid surface like a work bench.
When the bolt is removed use a small wire wheel on a Dremel and gently do a quick tap on the area that snaps onto the ram shaft. The parts were machined with very close dimensions so that they would be tight from the factory and then could loosen up with wear. The wire wheel is just speeding up the wear in process.