The culture of an organization is defined by the leader at the top.
The people working in the organization exhibit the culture through their daily actions. There are thousands of articles written on this topic.
What do you do as an executive leader when you recognize the organizational culture is not what you want?
Whether you created the culture as the founder/entrepreneur or inherited it as the new leader, the recipe is the same. First, you need to diagnose which attributes in the current culture are good and which ones need to change. This is particularly difficult for a founder, or legacy leader, as it is difficult to see since you have been surrounded by it for a long period. You might need outside eyes to help.
Second, you need to define your desired culture. Share it with your key deputies for input. Make adjustments as needed to ensure everyone is on the same page.
Next, communicate the principles of the new culture to everyone on the team. The communication needs to take place as often as possible. It will be an ongoing action, into perpetuity.
Most importantly, live the culture personally and consistently. Hold everyone accountable to it and ask that they do the same to you.
You define the culture. Make it what you want.