I still occasionally receive requests or questions about how to unsubscribe from my old football calendars. The main thing you need to know about this is that I never put the events on your calendar in the first place. The only way the events got onto your calendar is when you subscribed. Therefore, the only way to remove them from your calendar is if you unsubscribe.
Unfortunately, I can't do that for you; it's just not technically possible. If you don't know how, perhaps you can contact the support service for the calendar program you use. The following links may also be helpful:
If you have links to instructions that you think others may find helpful, please let me know so that I can add them to the above list.