When we took my sons apart, we took the neck bolt out,and put the whole front wheel assembly in the vise and beat it out using a 1/2" deep socket as a punch. It was mushroomed over on one side, so it only came out one way. We did'nt need heat, once the axle finally started moving, it came out slow and we had to add an 12" extension to socket to punch the axle all the way through.
Good Luck!
Scott