They actually sell small animal nail clippers, but my cousin broke mine. -glare- I just use human ones, they work fine. To actually clip them, hold your pig firmly, but not restrainingly, and just clip a little bit. There's a bit of white at the base of the nail called the quick. If you clip that, it will bleed and hurt the pig. So be careful. It's harder to tell with black nails, so be extra careful on those ones! If you can't get your pig to hold still, wrap him/her up in a piggie burrito (towel) and try. Good luck!