I have to agree. Nobody will change unless they want to.
They may even swear on their life that they will change, you will even believe it for a short time, but it will never happen.
The problem of course is that some take a very short-term view, and may only wish to show this change for the rewards that may be offered.
Unless that person truly wishes to move on - it will never happen.
Too many lives have been wasted by people trying to alter another who will never change.
In short never waste your precious life trying to change someone who will never be moved.
In this case grass may be greener on the other side!