How to re-apply a report template to an existing report
From your home page, open the left side menu and click Report.
Locate the reports you'd like to apply the template to, on either the Scheduled or Unscheduled tabs. Tick the box(es) next to the report(s) where you'd like to reapply a template. Then, click "Apply Template" at the top of the column.
Choose the template to apply, then click "Apply Template".
The template will then overwrite the existing contents of the report.
Note: Please use caution. Once overwritten, the previous contents of a report cannot be recovered.