steering wheel

[chumbucket]

They probably have corroded into each other. Try hitting the end of the helm shaft with a solid block of wood and a 2lb hammer while someone else applies upward pressure on the wheel. I had my Dad pry the wheel with two pry bars while I hit the end of the shaft to remove mine.
The only other thing I can suggest is to apply heat to the thing. Since you're replacing it anyways, you don't care about melting the plastic wheel. Someone will still have to pry the inner aluminum part of the wheel hub.
:P