Connecting pvc to cast iron pipes may be a daunting task to someone who is not a plumber but it can be done with ease. There are some simple steps that need to be followed and lots of diy places that can help. You must cut the cast iron pipe and then use couplings or tees to transition to the PVC. Then after placing your couplings in place and tighting them with the cast iron you are ready to
. place you PVC. Once these are tightened in place you can go ahead and glue it in like you would any PVC. For more information you can visit this website: http://www.ehow.com/how_4968998_connect-pvc-drains-castiron-pipe.html