glitch in adding turn signals to 1942 Pontiac

I purchased a turn signal kit for my 42 pontiac. I have everything hooked up but the tail lights. My problem is how to connect the turn signal left and right wires to the lights without both of them blinking at once. How do you isolate each side so the right will blink when it is supposed and the left when it is supposed to instead of both. The wiring is set up this way on the car so both will work at the same time, of course. The diagram that came with the kit only shows one wire going to the tail lights. Can someone please help? I know this can't be near as complicated as it seems. Thanks much ! David

The wires need to be cut so the power goes through the turn signal switch witch will cancel each side there should be 2 color coated wires coming from the turn signal switch that need to be hooked to right and left rear sides the brake lights go through the turn signal switch hope this helps Tom

Tom, thank you for the reply! That certainly helps! David