Navigate to the "AWS Cloud Formation Templates" menu item in the left-navigation pane (under Cloud Management). Once you are there and locate the Cloud Formation Template of interest, simply click on the template's name. You will then be presented with the details of the Cloud Formation Template. You can make edits to the template on this screen. If you do not have any Cloud Formation Templates specified, you simply click the button named "Create Cloud Formation Template" instead of clicking the name of an existing template.