I really want my partner to change and don't know how much to get involved. How much should I involve myself in his/her transformation?
If you think of the stages of the butterfly, the beautiful butterfly had to get through the stages of pupa and chrysalis before it could be coaxed out of it's cocoon and become one with its environment. To aid a pupa by removing its cocoon prematurely would result in its ultimate death. The pupa must struggle and toil on its own before it has developed the capacity and timing to free itself from the binds of the environment it was a slave to.
Express your expectations to your partner for what you desire in your developed butterfly but, above all else, give your butterfly the space to find itself and experience that freedom lost if we were to have intervened before it found its capacity resulting in its destruction.