How can i expose a person for who they really are .Her boss think she does no wrong but she is a lier & more?

This person is trying to get rid of people who have worked in the company alot longer than her.People that have worked hard to get where they are.The strangest thing is she can convince the main bosses that everyone else is the problem.Its almost as if she has come and taken their soles.The main bosses at one time (pryor to her)were very caring people,even godly people .I need help exposing her for who she really is!