How do I remove a cast iron pipe from an elbow with out breaking the elbow so I can put in a pvc why for a sink and toilet?

How do i remove a cast iron pipe from an elbow with out breaking the elbow so i can put in a pvc y for a sink and toilet?

You first remove the lead and oakum poured lead joint. To remove a poured lead and oakum joint take a 3/8" drill bit and drill a few holes down past the lead and into the oakum.. Push a screwdriver under the lead ring and lever it up. Once it's free you can began to peel the lead ring out. Now pick out the oakum and you can pull the joint apart. But that's the easy part, You will have to use a Fernco or Duel-Tite donut type gasket,(see image) to transition to PVC from cast iron.
Let me show you how it's done. Purchase a can of Duel-Tite Lubricant and slather it on the gasket to fit it in the hub. (you diid clean the hub off didn't you? ) . Inserting the donut in the cast iron hub was the easy part. Cast iron's hard enough to get in the donut but PVC's going to be harder. Back in the 80's I was roughing in condos with donuts, ( I hated them) Let me tell you how I shoved PVC into a cast iron hub using a dsonut.
Take a file, or a gtinder, and bevel the edge of the PVC on a 45 degree until it's smooth. NO ROUGH EDGES! Nexttake a sharp knife and bevel the inside edge of the donut back a few ribs.
Slather the inside of the donut and the outside of the PVC with lubricant.
Start the PVC in the donut. You're not going to push it in with your bare hands.
We used a Johnson bar for leverage. You can use a 4 to 6 foot 2 X 4.
Making sure the fitting isn't cocked and perfectly straight proceed to lever that sucker in until it bottoms out in the hub.
As a added note, Another option would be Soil Seal,(see image). That might just be your easiest way to go. I would pack, (and I mean drive it in) the joint with oakum and seal it with Soil Seal. Good luck, Tom

Thanks I will give it shot