I don't think there's anyone who would say that cultural change is easy, and this article states 4 ways to  develop a performance culture:

Accountability - Value and Results

Cut Through Communications

Learning Environment - Growth Mindset

Excellent in Execution

I'd fully agree with all of these. Initiating any cultural or business change without a clear intent to hold people accountable for adhering, or not, to the new culture is destined to fail. Big C and little C communications are valid, and this extends to both conscious and unconscious role modelling behaviour. Developing your people to better enable them to behave in the way which your organisation needs to succeed is vital. And finally, a focus on execution is what will separate your successful change programme from the 'almost-theres'. 

However, I don't believe that culture is the biggest lever you can pull in your business. At Collingwood we look at an holistic view which takes into account 'culture', 'structure' and 'strategy'. It is my belief that the biggest lever you can pull is the combination of these 3 elements - working out the correct recipe where all 3 are cohesive and supporting of eachother is what will enable your change programme to be successful.