Reduce all pseudo-academic busywork. Replace with recess, a real lunch hour, and creative electives of the student's choice (like for all Friday afternoons). Recruit regular teaching staff and parents to teach these classes.
Start with core homeroom in the morning. Then sync subject times across classes in the afternoons and ignore all ages and grade levels in favor of letting kids go to the class they need. The goal being that every child is working at his or her best level and learning every year (annual goal -- no one goes 'down' a grade by the end of the year). Homework only for independent projects or needed catch up.
School must implement a good anti-bullying program for students AND STAFF. The school should foster a culture of respect in both directions. The school should embrace intellectualism rather than achievement (the second should follow from the first, but without the first, it's hollow).
I believe all corporate culture is driven from the top down and supported from the bottom up. Without conscious direction, you get whatever culture survives the chaos. The admin should create a new motto, new guidelines, and a new handbook that reflects its core values. Students should be encouraged to participate in the crafting of these items as well as the culture at large through contests, surveys, homeroom projects, art, classroom decor, etc.
Focus on achievement, test scores, standardized tests, and winning should be reduced or eliminated as much as possible. Focus instead should be on learning for the sake of learning.
