Tips to Change an Organizational Culture
Noor, you need to decide what sort of culture you are trying to build. You do not say whether it's an army command and control thing (presumably not) or whether you're trying to achieve getting results by management, planning, leadership etc.
I'd start with trying to articulate and write down what you want the culture to be like. Use some examples to illustrate the points. For example "When people get things wrong..." "Managers respond by..."
List your desired reactions, discussion, coaching, mentoring, informal training whatever.
Collect examples as you go of behaviors you see that you want, and that you don't want.
Share them with your team (without naming names). It's a long process and some people won't change - you need to decide if they are people you want in your organization in the future.
Look out for the negative influencers. One person with a strong personality can influence the thinking of entire groups...