When you buy the clevis pin, take a few moments to make sure the holes in it are clear with no burrs. The one I bought had nasty burrs on each hole and those burrs will stop the spring and detent pin from going through. Just take a drill bit the size of the holes and run it through, then take some 200 grit wet/dry and buff the outside of the pin nice and smooth. The smoother you make the outside and inside of the holes the smoother the tool will work. When you go to use it just put the clevis pin in place, line up a hole in the pin with the hole in the receiver, drop the spring and detent through the hole and use a small punch to push it down, once the detent clears the clevis rotate the clevis 90 degrees. When you push the pivot pin through as you push out the clevis pin everything is held captive and there are no detent and spring flying around the room. Very slick set up.