I know exactly what you're talking about, but I don't really have the space for a tool like that- I've seen the size of the garages you folks have in the US.
There is also a hydraulic press I can access at work, so I might give that a go. I take it you pressed against the bottom of the aluminium hub?
The press I am talking about is rather small, between 4-5 ft tall and 2 ft wide, 2ft deep max:
http://www.harborfreight.com/12-ton-shop-press-33497.htmlYou could probably rig up something with a bottle jack just for this if you wanted to, then dismantle it after the wheel is freed up.
If go the press route, have the assembly resting on blocking from either side with the bottom of the wheel resting on the blocking and the shaft passing through and hanging down.
Leave the nut on the top of shaft for now and press down on that. The wheel stays stationary and the shaft is then pushed down.
Leaving the nut in place serves 2 purposes:
1: When it frees up, it prevents the shaft from dropping through and clunking on the floor
2: It prevents the threads on the top of the shaft from mushrooming or deforming due to the pressure of the press.