Welcome, diskman. It's been quite a while since I pulled an axle, so I'm going from memory and happened to be talking to AMarshall about this a few days ago.
Remove wheel, drum and brake parts.
Remove four nuts holding axle retainer plate in place.
You should now be able to pull the axle out. You might need to use some persuasion like a slide hammer if it's stuck.
You will have to get the axle bearing removed and the new one pressed on. There is a seal on the retainer and also an inner seal, if I recall. If so, the axle bearing needs to be packed with grease.