What are you trying to remove the rims & steering wheel from?
Generic advice for the steering wheel: if you've removed the nut, you can spray some PB-Blaster on the splines, let set a while & then crank the wheel from lock-to-lock a couple of times, then yank on it hard.
Or, you can loosen the nut, back it off to the end of the shaft (but don't remove it), pull "out" on the wheel (increasing the tension on the hub/shaft junction) and have someone whack that shaft
(
) with a mallet & brass drift. That
should pop it loose.
HTH!
Angel