How do you get back at your ex best friend?

I really wanna show that bitc* something. I would mess her face up but i would go to juvi. How can i mess her life up without physically hurting her? She is a lier, backstabber, and a trader. Shes been hanging with these new girls since after xmas break and shes been acting differently. I wanted her old self back but she grew more bitc*y. I wanna stab her. But i cant. Help me plz