I am installing a HiLo Industries model 1100 EZ pump to provide me with a toilet and lavatory on my lower floor. I need to connect the discharge (plastic) to my cast iron plumbing. There is a cleanout with a 3 1/2 inch brass plug in a convienent location to make the connection. I will add a new cleanout in line with where the old one was at the other end of the added pastic fitting. I think the threaded adapter is installed using oakum and lead. How difficult is it to remove the plug and the associated threaded adapter from the cast iron hub and replace it with a plastic adapter? Is it something I may be able to do myself, or should I contact a plumber?