You will have to read the book for that. Principals must be free. Principals use measurable goals to establish a culture of achievement. Master teachers bring out the best in a faculty. Rigorous and regular testing leads to continuous student achievement.
Achievement is the key to discipline.
Principals work actively with parents to make the home a center of learning. Effort creates ability. Nobody says it will be easy, but we can save our schools and, therefore, our students. Indeed, we must save our schools and, therefore, our students. It is worth the struggle to do so.