I have a snake head trapped at an elbow in a cast iron drain pipe where it is joined by a 2" vertical steel drain pipe/vent. I am advised to have the basement floor jackhammered and the pipe replaced. I propose to cut the steel pipe 6" above the floor, drain the water and take out an 18" section of pipe to get at the snake head and rejoin the steel pipe with hubless connectors. I could really use advice.