Not sure about replacing the metal pull but if you call Patagonia they will definitely send you a paracord pull, and there's are some guides on installing them! Quick Fix: Replacing a Zipper Pull and Zipper Pull Replacement

Hey Douglas! I think you could easily do an adhesive patch yourself if you like the aesthetic of it! But now that's its getting warmer, its also a really good time to send it in to Patagonia. They will do a sewn patch, not an adhesive one.