Great Books Curriculum

I am currently on the school council at my children's Catholic school. We are looking at converting to something similar to a Great Books/Classical curriculum. One that focuses on the relationship between faith and reason, that they don't contradict each other. I know this is a foundation for many who homeschool but we are wondering how to do this with an existing Pre-k-12 school. How do you revamp a curriculum and train teachers? Anyone have any experience with this?