Lead Joint?

You can cut the hub off, Fernco makes a coupling for that.

Yes that is a lead and oakum joint used on cast iron pipe. The pipe is placed in the hub, oakum is packed in around the pipe. Melted lead is poured in the hub to keep the oakum in place. When the oakum gets wet it swells and makes a water tight joint. You can remove the lead fairly easily with a hand drill and a small drill bit. A drill bit that will fit between the pipe and the inner edge of the hub. You simply drill holes in the lead, one right next to the other. Lead is soft and will drill easily. Eventually you will get some movement in the pipe and the remainder of the lead can be gripped with needle nose pliers and pulled out.
No, you cannot heat the lead and melt it, the pipe will absorb the heat faster than you can supply it.


You can put a piece of PVC in the hub but you will have to find the correct size gasket. There are two types of cast iron pipe, regular and heavy duty. Their inside diameters are different. Then you have to get the PVC pipe in the gasket. It is a very tight fit and you can't just pound it in. You would have to set up some kind of leverage system with 2X4s to push it in.


You can easily cut the cast iron with a chain breaker but you will have to open up the floor more to have sufficient swing room.


You can cut the cast iron pipe with a sawsall and Lenox Diamond Cast Iron blades.