Use cPanel's File Manager to delete individual files or folders from your cPanel account. Note: It's a good idea to create a backup of your website before deleting files or directories.

Warning: Make sure you don't need a file or folder before you delete it, or your website may stop working as expected.

From your client area go to:

Services -> My Services -> click on the green "Active" button -> Login to cPanel/Control Panel

In the top left-hand corner of the account Dashboard, select File Manager.

In the cPanel File Manager, select the file you want to delete. Select X Delete.

(Optional):

Select Skip the trash and permanently delete the files. Select Confirm.

More info: For more help, see the cPanel documentation for File Manager.