Occasionally, you may need to change the information in a client's record. To do it, follow these steps:
Click the
Edit icon on the Client Home page. The Client information page will appear: 
To modify an item in the client’s data, click in a specific text box to enter data, or use the Tab key to move from one text box to the next. The following data fields are required:
Contact Name - This is the name that appears in the Clients list. The contact name must be unique in order to work with it in the Plesk system.
Login - By assigning a login name to a client, you grant that user access to Plesk for independent account administration. Each client's Plesk Control Panel login name must be unique in the system.
NOTE
Use only alphanumeric symbols in the login name.
Password - You must assign a password to each client for security purposes. When entering the password, the symbols will be replaced by the asterisks so that nobody can accidentally see your password on the screen.
NOTE
Do not use quotes, space and national alphabet characters in the password. The password should be between 5 and 14 characters long and must not be the same as the login name.
Confirm password. In order to make sure that you have entered the password you wanted, re-enter it in this field.
Review the entered information. Edit data in any text box by clicking and editing the specific word or phrase.
When you are satisfied that the information is complete and correct, click OK.
IMPORTANT
Changes to client's email address will not be reflected in Start of Authority (SOA) records of client's DNS zones until you rebuild them by switching zone off and back on, or by modifying the zone.