If that is what I think it is, it is pretty simple to do. All you do is cut small slits in the strip of leather, and alternate sticking one end of the strip through the slits. If you already have one done this way that you bought, or know someone who has one you can easily take it apart, and put it back together. I had a custom sheath made for a knife at a saddle shop of all places, and they put a lanyard on the knife like the one in your picture. I liked it, and curiosity got the better of me so I took it apart,and put it back together to see how it worked. It is very simple,and looks very good in my opinion. The best way I know to tell you is to lay out a strip of leather, find the middle point where the leather will fold around the lanyard hole, and mark it. Then cut slits on both sides of your mark at even intervals. Slide the strip of leather through the lanyard hole, and alternate sticking the end of the leather strip through the slits you made. You might play around, and see what kind of spacing works best for you, as far as how tight your pattern goes. You may even play around with how you cut your slits, as far as the same direction as the length of the leather strip, or the opposite direction. I would prefer to go with the slitting in the direction of the strip because it would probably be stronger....
I hope this helps.........
