When to Change Stylus Tip

Been noticing a slight scraping sound when I write on my Tablet lately. Haven't seen any scratches because of it, but it occurs to me that I've never seen any directions on when and how to change the tip. I know that ring clamp thing is meant to be used as pliers, but I had to figure that out from the design. Seems like quite an oversight, not just by Electrovaya but Wacom since I use their eraser pen as my primary. Sure, it doesn't take a genius to figure this stuff out, but there are a lot of people less tech-savvy than me.