Log in to GreenGeeks and go to cPanel by clicking the “cPanel Login” button in the “Quick Server Login” section.
In the “DOMAINS” section, click the “Addon Domains” link or icon.
In the “Modify Addon Domain” section, click the “Remove” link for the Addon domain you would like to remove.
Click the “Remove” button.
Note: The directory that your Addon domain points to will not be removed. If you no longer need the directory you can delete it via FTP or by logging in the cPanel File Manager.