I am replacing everything from the flange to the on my toilet drain, and have purchased what materials I thought I would need ahead of time. One question is I bought a flange (pvc) that uses a rubber gasket instead of the wax ring, should the top of the flange be flush with the floor or slightly lower? Also I don't know what the existing flange is made of, there is a 4" lead elbow coming out bottom of the floor going to a cast iron tee with what looks to be lead gasket, how hard is that to get apart?