Once you save a task list template you can edit the template directly. Alternatively, you can create a task list template from scratch.
1. Go to Manage my organization.
2. In the left navigation panel, select Task list templates
3. In task list template you wish to edit, click on Add new task for this template to add more tasks.
4. You can also edit existing tasks by clicking on the down arrow next to the task and selecting Edit. You can do things like add subtasks and update the description, update the due date and more. Once you are done making changes, be sure to hit the Update button.