This was posted July 5th. Wished they'd reply and tell us how he fixed it... Or if he just took it to a shop.
Since they didn't I will.....just what I'd do not gospel.
Automatic Transmission Fluid and Acetone....yeah, they don't mix but the acetone helps pull the ATF down the shaft.
The above link was originally from Home Machinist magazine. I've tried it and it works.
Heat is your friend. Propane torches are all but useless, MAPP gas less so, but oxy/acetylene is the ticket. Heat the exterior of the pulley hub til just barely red and let it cool. This breaks the rust bond. Do not use the ATF/acetone while the unit is heated...acetone flash point is quite low.
Those two holes in the pulley can be used to pull it off with all thread rod, a couple of nuts and a puller bar. I welded up my own years ago...just two parallel steel 1/4" strips with a nut welded in the center for a bolt and two blocks on either end of the strips welded to hold the ends together providing slots for the all thread to pass through either side of the center nut. You can buy one, too, from Amazon.
Do NOT use jaw pullers as they will destroy the pulley. Use the bar puller and apply some moderate tension, heat the hub and it should start to come off the shaft.