Removing cast iron soil pipe extension

[bemused]

I'm hoping to fit a new low-level, close-coupled toilet and need to remove a short extension that is in place that used to couple with the old pan. The soil pipe and extension are both old style cast iron and when I started to dig out the putty-like filler at the joint I seem to have hit what looks like solder.

[attachment=0]IMG_1880x.jpg[/attachment]

The picture shows joint with extension piece covered by plastic bag.

It's starting to look like a tricky job to get this extension out and I'd be grateful for any advice.

[plumbbob]

The extension pipe is most likely to be a lead pipe. Break the putty out and remove the lead pipe section.

Clean the joint and replace with plastic pipe using clear silicone as a sealant.