Values are critical– not just what you say but what you own. You don't think your way into a new way of acting; you act your way into a new way of thinking. Say you want your church to be more missional. You have to start doing it. You personally– even if you're a leader who isn't terribly gifted at reaching out. In fact, even if you're abysmal at it, your people will see you trying and will be encouraged to try it too. Some of them will be much better at it than you are. And values, both individual and corporate, will shift along the way as you live into the mission.
So model missional ministry and empower people to start pilot groups that reach out. Who can you release for a more focused missional ministry? Who do you know who's gifted in that way? Empower them, bless them, support them, and get out of their way.