Changing the settings and limits of a cPanel account from WHM is a simple process and only takes a few minutes. This process is useful when you would like to make minor changes to an existing package for a specific user only.
1. Login to WHM.
2. Type "list accounts" in the search bar and click on the option below it. If it is displayed in the middle then you can click on that too.
3. Search for the domain you wish to make changes to and click on the expand option [+] on the left of it. You can now click on "Modify Account"
This is the page where you would be able to make some changes to the existing package without affecting others that are on the same plan.
4. Click on "Save" to confirm your changes.