The prerequisites
Nobody should be forced into Agile Working
It will take some time until miracles happen
It takes commitment to rigorously stick to roles and processes (similar as when learning to play music in a band - because if you start to exchange instruments during the show (roles) or you change the order of the songlist you're playing - chaos and confusion will be the result
It is hard to learn to work in an agile way by just reading books.
Only by using the principles and applying them in practice will help you become good at agile working.
Theory is great to get an idea of what is the purpose of agile working and to put experiences and learnings into a greater context.
Agile and non agile work forms should not be applied at the same time, however they can coexists.