In my former employers company, the two employees with the greatest tenure (20 years) resist change the most. They have positioned themselves as indispensable by not sharing their historical knowledge about our legacy system. As a result, they are constantly being consulted for assistance on which reports to run, or how to overcome a system issue. What can be done to mitigate this risk when "dinosaurs" don't want to play in our sandbox? (no offense to the long term employees in the audience)