You can edit templates to change the properties, such as the name of a template and the number of days before and after Day Zero. If you reduce the number of days before or after the Day Zero, tasks associated with those days are removed. Editing a template has no effect on schedules previously generated from that template.
You can edit, copy, and delete tasks in a template. See Editing Tasks.
You must be working in the source template to edit tasks from embedded templates.