I tried a pipe wrench, but wasn't able to budge them. I could cut them flush with a Sawzall ... to move them because there probably isn't a joint to unscrew. In the olden days, the fittings ...

In some situations using oakum to seal a cast-iron pipe joint is still a viable option. Step 1: Remove lead and oakum remnants from the joint to be packed. Clean and dry the joint thoroughly.