should I replace the lead bend

[rblick]

I recently broke open my basment floor to replace galvanized drain pipes for a bathroom remodel.

The toilet drain is an old 4" lead bend. It appears to be OK. Do you think it is worth the effort to replace it. It is leaded to 4" extra heavy CI.
I'm afraid it will be a can of worms if I try to remove it.

[rblick]

ok, I'm updating my post after doing some research. It appears that the most common way to replace a lead soil tube is to cut and melt lead away from the brass nipple and then attach PVC with a fernco.

My question is, where to cut. At the point where the brass nipple and lead come together there is a raised lump around the perimeter. A ferrule I guess. Should I cut before this ferrule or after? Is the ferrule part of the nipple? Will the fernco fit over it?

http://www.terrylove.com/images/replace_lead_bend.jpg
Or use plastic fittings and a rubber hub donut.

[Winslow]

leave the ferrule in place and cut the lead after it. The fernco band onto the ferrule.