I want to Migrate Domain/Hosting From Old Client to New Client.
How can I do that?

Also When Migrate to New Client  Here will be option Email to both Customers to know Away and Incoming new Services.

Manage Service: Ultimate Hosting - demo.com
Manage Service: .com - Demo.com
Previous/Old Client-
Name: John Peter
Company: Demo LLC
Email: john@demo.com

Current/New Client-
Name: John Doe
Company: Demo Services, LLC
Email: doe@demo.com