Get some Ofna molded foams, bake your tires off the rims, and install the new foams/reglue the wheels.

350F for 10 minutes, then turn the oven off and let it cool with the wheel/tires in there is what I do. The glue comes undone, and badda-boom badda-bing, you're done. Let them cool completely before touching them though...HOT RUBBER HURTS!