Can someone guide me through replacing Snapper rider rear axle?

I didn't replace the boots on my 9 yr. old rear engine snapper (281016BE) when I should have. Kept putting it off. It got to where it wouldn't go in reverse so I had to do something. The other day I took it in and had a man replace the boots and tune it up. When he had it apart he called and said the axle had a groove worn in it right where it went through the fender. The top of the axle bearing had blown out and the axle had been rubbing against the fender and cut a groove in the axle. He said it was my call whether or not to replace the axle when he replaced the bearing and boots but he thought it would be ok. It was several hundred dollars more to do this and I opted not to. He said the groove was right where the new axle bearing would be and should support it some but would not guarantee that it would not twist off from torque. Well, on my second usage that's exactly what happened. Now I have to replace the axle. Both hubs should be easy to remove since that had just been done. Can someone walk me through the axle replacement? I think I can do this if I know the "tricks" in advance. I think I remember you only have to take one hub off.
Thanks so much in advance.