Generally speaking, I don't think you can just inject agility into an organization. I know there is an entire consulting industry based on this idea, but it's a flawed and expensive premise.
I can't quantify or prove this, but I think you'll find that most agile organizations evolved their way into it. They were willing to:
1. inspect, reveal, and recognize the need for change
2. research and explore better ways of working
If your organization isn't willing to do this, they won't become more agile. There's nothing you can do to make it more agile if it won't accept transparency or if it refuses to adapt. And if you approach it with a "methodology" approach, then at best you'll be providing another organization's solution that may or may not fit your organization. Saving Changes...