Your account in Plesk stores your access credentials and contact information, such as email, address, and phone number. Depending on how you subscribed to a Plesk reseller plan, you may be able to choose your own username and password or receive them from your hosting provider. To change your account password, click the Change Password link in the navigation pane. If you forget your password and are unable to log in to Plesk, click the Forgot Your Password? link on the login page and enter your username and the email specified in your contact information. Upon submitting this information, Plesk will send your password to the specified email address.
Note that your username can’t change by yourself
If you need to update your contact details in your profile or add or remove some of them, click the Profile link in the navigation pane or the link with your name at the top of the page. This will take you to a page where you can manage the details.