This is a much better post to get your point across than a simple "how do I bypass my school's web security?" You have to admit, it sounded a little fishy. 🙄
In the end, shouldn't your assistant principal be asking the principal, who'd ask the superintendent or something? It seems odd that the school administrators would be looking for a way to bypass their own security.
And if there is a way, your assistant principal should be concerned about providing a means to get around security to his students or staff (not sure of your part in this play). Setting up proxies would likely only work if you had another way to the internet outside of the main routers.