Below are the steps to remove or delete an addon domain:
1. Login to your cPanel account.
2. Go to the Domains section and click on the “Addon Domains” link or icon.
3. Then navigate to the “Modify Addon Domain” section and click on the “Remove” link for the Addon domain that you want to remove.
4. Next click on the “Remove” button.
Note: The directory that your Addon domain points won’t be removed. In case you don’t need the directory, you can delete it via FTP or by logging in the cPanel File Manager.