I think you know what to do! Your guides with shamans and plants from South America already told you if I remember correctly. Why can't the boys that were abused at your school get together and file a lawsuit against the institution and individual abusers?
I think the best way to express rage is let it go because it will eventually cause one physical and mental illness. After eradicating my rage I was able to articulate clearly the abuse I suffered and stand up to my families inability to admit they were enabling and protecting abusive family members whilst vilifying the victims of the abusers.
My rage spilled over onto innocent people who had nothing to do with covering up past abuse, it was like holding a burning hot coal in my hands. I had to let my rage go to heal and be a good mother, friend, and wife.
One can go after preditors without tearing oneself apart emotionally. That to me is a spiritual warrior, then one will avoid becoming what one has been fighting.
RE: How do I express my anger at the School that abused me?