How to delete a report template
From the root of your account, navigate to the "Templates" control panel via the left side menu.
From within the "Reports" tab, tick the box next to the report template that you'd like to delete, and then select "Delete" to confirm your choice.
Note: Deleting a report template will not delete any client reports you've created with that template. Once you create a report from a template, the report becomes a separate stand-alone report.