Cutting through cast iron How is it possible to cut through a cast iron soil pipe

In my bungalow, I would like to rotate a 4" cast iron "Y" 180 degrees, which is inserted on a verticle wet/dry vent. Can this be done by heating the lead and turning the "Y" in the position required. All the walls have been removed to remodel the bathroom. So I can use leverage to turn the "Y" ...

I'm adding a room to the house that requires footers. In the course of digging the footers I found my sewer line. Not a problem except that it is Orangeburg style pipe (tar paper tube). Before I build over it, I want to replace that section then eventually replace the whole line to the street....

Anyone have any tips on the installation of a cast iron tub in an existing alcove. Would like any advice on putting the tub into place so as to minimize injury, strain, frustration, people running over each other, etc.

What do I put an old cast iron tub on. Can it sit directly on a new ceramic floor? Would I have to put something under the feet? It will be quite heavy with water in the tub.