Get a group of parents togethe; enough to plan the attack and spread the workload and, presto, that's a start. It would be an incremental process building membership and voice as time passes until the parent group reaches a critical mass.
They will know they have reached a critical mass when, for the first time, they attract the attention of the school principal and/or board of supervisors. That, in fact, is Goal # 1. Pure grass roots stuff, Pam.
From there on, the attack would focus on the core curriculum and then start folding in ideas like your own in your last post
Wish I was about 40 years younger.