John Kotter published The Key to Changing Organizational Culture on Forbes. Kotter talks about how to, and how not to, change a company culture.
How does culture change? A powerful person at the top, or a large enough group from anywhere in the organization, decides the old ways are not working, figures out a change vision, starts acting differently, and enlists others to act differently. If the new actions produce better results, if the results are communicated and celebrated, and if they are not killed off by the old culture fighting its rear-guard action, new norms will form and new shared values will grow.