Well simply put, you can't prevent trolls from coming to your team. You can only make your server/team less attractive to trolls in the first place (which it seems you've already failed at if someone felt the need to make this post.)
Sacrificing is easy. You just need an altar, a statue honoring baphomet, a pentagram drawn in lamb's blood, a virgin (no shortage here) and a whole lot of chutzpah. xD
But seriously I don't need to explain exactly how to sacrifice the trolls you find. Use your imagination. One must think like a troll to out-troll the troll.
Haven't you ever crossed a bridge???