I bought some cheap replacement styluses for a gadget with a plastic pressure-sensitive screen (a Wii U gamepad). Being cheap, the seams between the styluses' plastic halves are not well sanded, and the tips have varying degrees of scratchy protrusions that might damage the gadget's screen.
What's the best way for me to smooth them down myself? Just a certain kind and grit(s) of sandpaper? If so, what kind/grit? If not, what else? I am extremely beginner level with this sort of thing, so you probably shouldn't assume I know even basic facts.