Quick Internet Research--Reflected that other models of that same bandsaw did not have any set screw holding that main drive pully onto to the shaft. See, for example http://www.targetmanufacturing.co.uk...Parts-List.pdf
It looks like a regular two jaw puller would work, but if the holes in the fan are too small for the puller arms, then search for "thin two jaw puller" for many options with thin arms. You're going to be well equipped for pulling stuff by the time this job is done!
That's a nice cast fan and probably not very strong. I would snake a wire between too adjacent holes and form them into a loop that I could get a slide hammer on. Then I would take a hot air gun and heat the fins at the base around the shaft and when hot pull it off with the slide hammer. Wrapping some kitchen foil around the outside of the fan's fins will help to contain the heat. I'd worry the gear puller would break the fan if used on the outside.