Train the people selected to be Mentors. Establish and distribute the Mentoring assignments and schedule. Track performance of the field location applying the new play book. Once performance meets expectations, the Mentors are reassigned. Identify several mentor candidates rather than just one.
Peers can be an excellent source of mentorship.
Would-be mentors are most receptive to people who ask good questions, listen well to the responses, and demonstrate that they are hungry for advice and counsel. Remember, it is not just the protege who benefits from the relationship. The mentor, as well, should see the opportunity as one for personal growth. They too will learn new skills and competencies.