[Delta3000]

Hey, I've had this old knife laying around for a good while, it came down from my grandfather, whom used it when in the navy. I've been trying to take it apart so I can polish it, and probably replace the plastic discs on the handle with paracord. Issue is, I can't seem to be able to take it apart, there's a pin on the back which seems to hold everything together (I don't know much about knives, I'm a firearm person myself). If anyone has information on this knife, or has tips on how to take it apart that would be great.