The Recently Cancelled Assignments tool here works just like its VSys One equivalent, showing you training records with a Status of "Cancelled by volunteer" or "Cancelled by staff" during some time period. Use the filters at the top to select the cancellation date range, start date, jobs, etc. Then click Refresh to load th assignments.
Click on the person's name to open their profile in a new window; use the Edit link to edit the assignment itself.
Changes made here are saved immediately.