How can XP or other agile methods be used in large corporate IT shops? One large company found out, making XP the official corporate software development methodology for all projects over an 18 month period and counting. This paper explores many facets of that experience, beginning with a summary of the eight key determinants of organizational change model. It then follows the organization in implementing XP, using the change model as a yardstick to assess the success of the hoped for change. The paper concludes with key learnings regarding how to implement an agile methodology within a large organization.