I have a late 60's house that has the toilet rough in approx 12" away from the wall, pics attached. I am in the process of refinishing the basement and would like to insulate, frame & finish the wall. In order to do this I need to move the toilet rough in 6-8" farther away from the wall. The drain is cast iron. The sink drain runs inline with the toilet straight into the main stack. Can I just break up the concrete, cut the pipe and install a tee so that I can move the new rough in to the right location? Do I have to go all the way to the main stack or can I just cut the old pipe close to where the current flange is now? Should I repipe the sink drain at the same time and do it all in plastic? I want to leave the sink drain in place if possible but if I have to move it I will. I'll be so glad to get rid of the UGLY carpeting!

Any advice would be greatly appreciated.
thanks,
Mike