In the 1980s, under the leadership of Lord King and Sir Colin Marshall, the British Airways undertook a culture change programme which was most advanced and successful in the corporate world. Here is a paper from HBR you can buy on how they did it.
Under the banner of "World"s Favorite Airline" they transformed themselves from a government owned British airline to one of the very best airlines ever. Every staff member was retrained, all of their service practices changed, and, as a customer, excellent service became a reality in the airline industry. Anyone who worked on that program, internal BA staff or consultant, was hot property for hiring to do the same thing for other companies. We were all so in admiration of what they achieved.