WhenI did one for the first time, I hired a country mechanic to work with me. The biggest help was the "splitting" stand that he had that bolted to the tractor and allowed you to roll away the other half.
The whole thing was no big deal. We only used a few tools and he mostly did the smart things while I did the grunt work. When done he asked for $150 and I gave him a real good tip. I would say it took a few hours.
If I were to do it again I would still get a shade tree helper and be an understudy to them. Something like a retired truck or auto mechanic, that kind of thing. I would not try to do alone or do unless you had a simple splitting stand with wheels on it. That takes all the risk away.