Please this is life threatning plzz help me?

ok so I iinng hate this ****** in my cl,In the beginning of the year I got 2 girls to get her in trouble,i told my art teacher that she was being racist but she wasn't she was still being a ****** though,and we even got the principal to talk to her and me,and then she started crying,but whatever she's still mean she deserved it anyway,she's foreign and she's in ESL,anyway I don't think this girl in my cl who I am friends with likes me anymore because I was being mean to her,but she is still being mean to me,my point is how do I completely ruin her life,without her knowing it me,like something really mean and sneaky!!Also I don't think I want to be friends with them anymore,but If im not i won't have any other people to hang out with during cl,don't get me wrong there are other girls in my cl I get along with but we're not best friends,and please help me I wanna stop all this drama and i want her to stop talking about me behind my back,i hate her sooo much!!