Hi there, I was about to put in a new toilet in 1st floor batroom but as I was knocking off some old plaster from the wall behind the toilet a hole appeared on the soil pipe at the back of the loo! I managed to make a temporary repair but I obviously need to change the whole thing as the hole shows that the iron is corroded.The stack outside is cast iron and only has the one connection to the toilet I mentioned earlier. I know that you can slice off the cast iron pipe with an angle grinder and then reconnect a PVC soil pipe but can anybody tell me how difficult or easy it is to achieve.Thanks in advance.