To split addon domains into individual cPanel accounts, you need to, in chronological order:
01.
Download a full cPanel backup of the original cPanel account (that has the addon domains) to your computer (one that you can use FTP to upload the data from)
02.
Terminate the original cPanel account.
03.
Create cPanel accounts for each of the addon domains.
04.
Upload the relevant files to the public_html for each website. Read this article for detailed guidelines on how to manually restore files, emails, and databases from a full cPanel backup.
05.
Refer to the wp-config.php for each website and find out what is the MySQL Database and Username, then create the MySQL Database and Username for each website (remember to assign the MySQL Username to the MySQL Database). Take note that since the cPanel username is different, you also need to update the MySQL Database and Username prefix in the wp-config.php file.
06.
Open up phpMyAdmin for the same cPanel account, and upload the .SQL file for the MySQL Database. The .SQL file can be found in the original backup file you made in step (1), located in the "mysql" folder.
07.
When opening wp-config.php, please also take note to check for any specific caching plugins that may reference a path like /home/username/public_html/addondomain.com, you should change it to /home/newusername/public_html for example.
