cPanel has added a new feature to the WHM to split an addon domain off to it’s own cPanel account on the server now. It’s very easy to use, however you do still need to do a bit of manual work. You need to know the names of any databases and database usernames the addon is using, as the tool can not detect these. So if you are not sure, start looking through any config files for your website to find the database name.
To split an addon, login to the WHM, and click on Convert Addon Domain to Account. This will bring up the list of ALL addon domains that are on the server. Search for the addon in question, then click on the convert button.
On the next screen, click on configure beside the databases, and select any databases that the site uses. If you convert the site without selecting the databases, then your site will no longer be able to access the databases. Once you selected the databases and usernames, click on “Save Selections” then click on the “Start Conversion” button.
The site now be in it’s own cPanel account.