Shared calendar problem

[Olive DiMantra]

Hey Members, 

With a friend of mine, we created hundreds of evens in a shared calendar, but our collaboration terminated. He needs his own events and I need my events from the shared calendar. How can I separate those events? 

If we export the shared calendar and then import it to our private calendar also impossible load of work because we can't delet the other one's thousands of events. Could anyone help to advice a solution? 

Thx