Attach the watch by sliding the two free ends of cord over the pins, under the watch, and back out over the other pins. Slide the watch to about what will be the halfway point between the two parts of the buckle once the other buckle is attached.

Loop onto the other part of the side release buckle, and loop it a second time so there are four loops filling the gap in the buckle. At this point you make sure the length is your wrist size and no more than a 1/2 inch more than your measured wrist size. The length tends to stretch out as you tie the half-hitches, so before you trim and melt the ends, try it on. You may have to untie it and reset the length making it longer or shorter depending on if it's too loose or tight.