I finally got some help and we used a hammer, believe it or not, on the old cast iron main sewer line... surprisingly all went well and we got all the fittings on... plumbing/venting, water lines done... wouldn't have happened without the help I received on here... much thanks and appreciation to this site and for those who help others with their knowledge and wisdom... peace...
massplumber2008, ballengerbl, mygirlsdad77, iamgrowler, milo... lol... thx to one and all... additional kudos to MassPlumber for thorough help... much appreciated one and all