Biwiring zu wax speaker cables

Hi all,
I just picked up a a pair of zu wax speaker cables form a fellow member here. They came single wired and I would like to reterminate them for a biwire setup. Does anyone know which leads go to the highs and which go to the lows? There are three conductors within each leg. 1 is a heavier lead and there are 2 thinner stranded leads. My guess is that the heavier lead goes to the LF posts and the 2 thinner ones go to the HF posts. Any help is appreciated.
Before surgery decision read bellow:

You can also buy thinner speaker wire from VanDenHul (Chris is extreamly knowlegable in these kinds of set ups to recommend the proper gauge and termination if important) for your HF binding posts and run two cables per each speaker. It'll save your time, get more efficient results and wouldn't alter the speaker cable to keep the value.