our company had a site that had users who had different levels of access on different sites and doc libraries, now we moved our company site to a different server and our domain name also changed due to some organizational changes. For example in the past a user was abc\john and now it is xyz\john . Is there a way that i can change the domain name for all the users at 1 shot? Users , usernames and permissions for those usernames should be same, We just have to change domain name. How can we do this?