I am finishing a basement. Currently, the light on the landing and in the basement is controlled by a single pole switch at the top of the stairs. A 14-2 wire comes from the box to the basement light where a 14-3 continues to the switch. From there to the landing light is another 14-3. Current continues there to the rest of the circuit. How can I change this to a 3-way with a switch at the base of the stairs with a minimum of rewiring?