I damaged one of my styli by leaning back and stretching my arm with it in my hand - it rubbed against a rough wall in a hospital waiting room, which scuffed it up at the tip. But it wasn't hard to polish it back nice and smooth again; it's fine now.

As for dissecting one - it's just solid plastic. Nothing fancy! You can use any PDA stylus, or any pointy object if you're careful and it's not too sharp. I often use my old Palm Pilot stylus.