I am replacing an old lead soil pipe, which runs through an exterior
wall to a 4 inch cast iron socket and will replace the lead with 100mm
PVC.

A 90 degree cast iron bend has its socket buried in the wall and the
lead is plumbed into the socket.

I will need to replace the cast iron bend and the next short length of
cast iron to a branch in the main soil pipe start. Fortunately this
is all at ground level.

My question is how do I connect 100mm PVC to the existing 4 inch cast
iron? I asked Marleys and they offered a push fitting for a 4 inch
cast iron spigget but I do not want to cut the 4 inch pipe, there is
no easy way of doing it in the position its in.

Ideally I will connect the 100mm PVC into the cast iron socket in the
branch on the main soil stack. How can I connect PVC into a cast iron
socket easily?

Thanks

Ian