1. Click on Products>Classes>Schedule.

2. Click on the 3 dots next to the activity you want to cancel/delete the schedule for, then click on Cancel activity.

3. A menu will open so you can decide if you just want to cancel that occasion or if you also want to delete it. If you select cancel and delete all futures then you have the option to choose the days that the schedule will be removed.

4. Click on the Cancel activity.

Keep in mind that if you delete a schedule, you cannot get it back. And your clients will automatically be informed of the changes so you don't have to worry about doing it.