In some situations, the best approach is to start your new piping inside an old hub. One example is when a stack hub rests at basement floor level and you'd like to extend a branch line horizontally just above the floor. There are times when using an old hub can also save you from having to cut into stack. Removing an old iron pipe from a lead and oakum joint is well within a homeowner's abilities. The job requires digging both the lead and oakum from the old joint so that you can lift out the pipe.
Special tools for this job are available, but an old flat-blade screwdriver will work just as well as any specialty tool. Begin by driving the blade of the screwdriver diagonally through the ring of the lead, prying it up. Grip the priedout piece of lead with pliers, and peel the rest of it out. You can dig out the oakum in a similar fashion, but you'll have to remove it bit by bit. Needle-nose pliers work well. When you have cleaned out the joint and removed the old pipe, install the new pipe.