You put the eye thru/in the ring, then open the eye and push each side of the eye around the ring... its hard to describe. Then you do it again with the other eye coming in from the other side so they're semi-symmetrical. Let me know if that doesn't make sense.

If you look closely at the first two pictures on page 1 you can see, not really how to do it, but that they are equal but opposite in the way they go thru both rings.