To remove a "No School" event, please follow these steps:
1. Click on the event as that appears in your plans, or click Go To -> Events and locate the event there.
2. Click the three-dot icon in the upper-right corner
3. Select "Delete".
If you are not seeing events appearing, you can ensure those are shown by clicking the "View" button in the upper-right corner of the screen and checking the box for "Events".