Steering box swap is probably a couple hours if you really dig into it. Mine took about 5 hours -

Have a beer while draining the system, unbolt the pitman arm, celebrate with a beer (mine dropped out pretty easily), drop the old box, have a beer, bolt the new box in, have a beer, help my wife unload the truck, another beer, hook up the new rag joint and hoses, have a beer ... you get the point

Had the rear end out to powder coat, so I wasn't worried about the blood alcohol content. Couldn't test drive that day anyhow.