Cast Iron Drain

My kitchen sink drain is copper that enters cast iron. The cast iron T is in the vertical stack, which then goes down into the concrete floor. I am remodeling the kitchen and need to move the sink. The T needs to be turned 90 – 180 degrees because the cabinets will be where the present drain line enters the wall. How is this done? Been told that the cast iron has to be cut, turned, and then somehow coupled back together.