I just recently clipped mine. You actually aren't removing any metal from the pin box itself, but remove from the plates that are part of the trailer that the pin box is bolted to. The first photo is how I clipped mine, and the second photo is where I moved the serial number tag to. I used my 4" grinder with a thin metal cutting blade. Be sure to wear safety glasses or goggles when you do this. Just a little work with a file and some black paint finished it. I also moved the wires in the flex tube that goes to the emergency brake switch to the next hole forward, and also relocated the metal junction box up so it isn't in the way.
