Management of Google generic accounts is through the Web Registry tool.   The options include password management, service contact updates, and name changes. 

Access Web Registry

1. Go to Web Registry.
2. Sign in with your Unity ID and password.
3. In the My Services section of the page select whichever Google Generic Account you are attempting to manage.
4. In the list that appears, click on the Description of the item you want to manage.

You should now be on the Service Details page of your Google generic account, from which you can perform all of the following actions.

Password Management

How do I view or change my Google Generic Account password in WebRegistry?

Update Service Contacts

Change Generic Account Name

How do I modify my Google Generic Account's name in Web Registry?