I tried calling them. No help. Anyway, I figured it out. And boiling does nothing.
1. Insert one end in the closed position. Shove all the way in until the entire yellow side touches the black side (flush).
2. Slide the other side down until it goes in. It is angled, so sliding down isn't too hard.
3. When you open up the latch, the first side will pop up out a little automatically so that the latch will be centered.
This is the same for both tstak and tough system.