As a Yesware user, you can create, edit, and manage your personal Templates. If you are a Team Leader, you can create, edit, and manage Team Templates and folders.
In your Outlook ribbon, select "Open Templates." On the page that opens, find and click the Template you'd like to update, and then select the "Edit" button at the bottom of the window. Make necessary changes and hit "Save Template." To delete a no longer needed Template, click "More," and then "Delete Template."
Note: any changes made will require that you close and re-open Outlook (as well as your Teammates).