This article by a Marine special operator says special operations have a culture problem. That doesn’t surprise me too much. Anyway, here is the prescription the author gives for addressing an organization’s culture problem:

• Acknowledge the problem. It’s hard to spot a slow change from within an organization. One solution is to have a peer organization do a review.
• Employ trusted agents. These are sort of the blue collar leaders.
• Harness and rein in the cultural power brokers. These are more like the middle management.
• Win the population. This is an idea for counter-insurgency where you try to peel the bulk of the population away from a few bad actors within their ranks.

The article mentions “core values”. My own observation about core values is that strong, well-functioning organizations tend to already have them implicitly, and when you have to make a big deal about training people in them explicitly your culture is already lost. I’m not sure you can change individuals’ core values all that much. You can try to weed out people with bad ones and bring in people with good ones.