The end of the axle shaft is a lightly press fit into the hub. If you hit it, you may damage the end and the nut will no longer thread onto the axle.
I used a 3 arm gear puller and some PB blaster and it came apart very easily. If you are replacing the wheel bearing, please do not smash it in with a hammer, you can destroy the balls and bearing surface and most likely will split the bearing apart. The inner race is a split design and will come apart. At autozone you can rent the tools, they will refund you the price when you return the tool.