To remove an existing template, simply click on the "X" icon next to the email you'd like to delete shown below in red.
Once you've clicked the icon, confirm that you really want to delete the template. Clicking "Yes, Delete" will remove the template from your list of available templates. Clicking "No, do not delete" will keep the template on your list.
Note (1): If you decide that you need to make the template again, you can always add a new template.
Note (2): The Stock Templates may not be deleted.