I'd try and get some good industrial penetrating oil on the shaft and tap it all around with a hammer, wait a day or two then use the hammer on the top and bottom to try to rock it loose.
Work his way up through the Fitting Hammer rack.......He's tossing it anyway, might as well have some fun and wail on it....
BT3 Taylor: IL Mechanicus Sledgehammerum
We had this BAH in the shop at the last facility I worked. One day in a fit of boredom, I inscribed (using a paint marker) on one side of the hammer:Hey Hawkmiester, those are VW tools you're referencing, what he needs is THE MIGHTY MOHLINAR. i.e the Hammer of Thor. You can get one on ebay for about $15.00.