What's the best way to put pressure on a school Principal?

There's a principal in our town that is absolutely horrible. Many students, parents and teachers have had problems with her and we want to get her out. The DOE (Department of Education) is too cowardly to get rid of her and she's very slimy. It seems that our complaints go nowhere and she continues to ruin the lives of kids in the community. What's the best way to put pressure on her so that she'll be held accountable for what she has done?