Along the same line as Brian's and Dan's (and Tony's) posts: Even an alloy spinner can stand some heat. A CO2 fire extinguisher is a good source of instant cold, as is dry ice. Heat the spinner gently until it's too hot to touch quickly, then give it a shot inside the hub with a CO2 fire extinguisher or apply some dry ice and rotate the wheel to cool it evenly. A few taps should loosen the spinner...assuming you're hitting it in the right direction.
