I replaced 2 pins in my trophy ridge flatliner. I had 1 pin that wasn't perfectly aligned with the other two, and tried bending it a little, and snap! Silly me. I contacted Trophy Ridge, and ordered 3 new pins. They are not expensive, and come with directions to replace them. Its not that big of deal, least wasn't to me. Simply have to push out one of the pins, unlock, and remove the pin by cutting the fiber where wrapped around the sight housing. I'd go that route. I don't really see how stringing the new fibers in through the plastic housing could be possible. Directions also read once a pin has been removed its no longer any good. Not sure why other then maybe it wouldn't be as tight or something. I simply heated up a knife, and touched it to the end of the fiber once inserted through the housing holes to keep it from pulling through. Contact Trophy Ridge they'll hook you right up, and get them to you fairly fast. Good Luck.