re: How hard is it to replace a section of copper pipe

Looked at it again this morning with a fresh set of eyes. It is 1-1/4 copper going down about 3 feet and connecting to a larger cast iron main drain pipe. I'll need two 90 degree pvc joints. One to go left after it enters the wall, and another to turn down to the basement. From there I think I can route it towards the pipe pretty easily since I'll have more room to work. What is common for joining PVC to cast iron? It does have a larger connection at the iron, I'm guessing 3 inch. From there it joins up with the 4-inch main drain further down, but I only need to connect to this point. The only thing going through this is the sink and dishwasher drain, so no need to go larger than 1.5 inch PVC.