Changing Data Protector Adminstrator Best Practice

Hello Folks,

Now I have a backup system running well with backup admin user :hpdpadmin

which is admin in the cell manager , backup server ( DP server ) , all the clients ( cluster , sql , hyper V cluster )

I want to change the user to another name. What I have to do ?

1. Do I have to add this user as admin in all clients?
2. Do I have to add this user as login in INET service in each client ?
3. How can i change the admin of DP cell ?
4. Do I have to change the login of the five services of DP application server?
5. For Microsoft cluster Do I have to add this user as admin in all nodes ?

I want to know what is the best practice and the exactily steps which i have to do in good arrangement ?

Can you help me ??

Thanks