You may research new curriculum. You may research what other successful schools are doing. Once the plan is developed, then there needs to be a written agreement that lays out what is expected of all the players and what is acceptable behavior. Secure support . Keep those responsible for implementation, those who will be affected, and those outside the school who have influence over the outcome aware of the plan and willing to lend support.
Talk is only talk.
Now you need to act. Public Relations is very important here - let your supporters know what's happening. Provide professional development for staff. Effective training is essential. The best training will provide staff with several opportunities to examine the issues, work together, and monitor and evaluate the progress.