By trying to end it, of course. It's kind of his job to keep the balance between the elements, and if you're Aang that means telling everybody to get along.

[ Toph sounds sarcastic, but also long-sufferingly fond. It's pretty clear that she'd gotten suckered in but still retains a sense of humor about it. She definitely had not set out to pursue world peace; she'd just been trying to exert her own autonomy and kick some ass. But once she makes a friend, she keeps them and doesn't look back. ]

Anyway, yeah, I can sense things in the air if they're made of earth. You're talking about bullets. [ Thanks to Caitlyn - and to a lesser extent, Vash - Toph is pretty familiar with firearms. ] It's tricky when they're moving that fast, but redirecting something is a lot simpler than stopping it. Why d'you want to know?