Removing the old tub with a sledge hammer I understand. But what about
Bringing in the new tub. Tub seems standard 60” long by 30” wide.
But the bathroom door space width is only is 23” and the doorway to the hall wall is
42” not much room to turn about.

How tall is the new tub? You should be able to stand it up and turn sideways so it can be slid through the opening. Removing the door will help

Thank you

I've had tub installations that required us to install through exterior wall but assuming your not
Going with cast iron , a furniture dolly with the tub on end should make it. Most built ins are aprox 20in.
In height so your door casing shouldn't be an issue.
Rojo