::When you create a GP Account, GP creates a SQL login (only usable from the GP Client., so it’s safe)
Assign the appropriate and necessary GP Security Roles to that GP account name.
–> In SQL Server Management Studio (SSMS) find that same name, as a SQL level login, and assign it the “sysadmin” SQL role. That account will now be able to add users inside GP (User Setup) and Assign Access.
Again, this account is still secure and safe because the login is encrypted and only accessible with the GP Client.