How to delete an expired iCloud account?

Hi

(the background:)

For some time now I have been having problems with iCal, and with my calendar on iCloud. There are problems with the communication between iCal on my MacBookPro, my wife's iCal on her MacMini and the iCloud calendar, but what is more annoying, I also began to get multiple duplicates of events on my MacBookPro's iCal. (I admit: the reason for THAT may be with the synching software between the MacBookPro and my Android smartphone!) Trying to get rid of all those duplicates at once, I deactivated iCloud in my system preferences and then deleted all calendars on my local iCal, planning then to reactivate the iCloud account and to restore the calendar from iCloud.

Only, it seems that I have painted myself into a corner.

(the problem:)

Whenever I try to activate the iCloud account, iCloud tells me it can't do that.

I open (iCal) preferences:

…go into «accounts» tab:

…click on «Diesen Account aktivieren»… and get this:

«"calendar" is unable to activate this account; there has been an unknown error.»

The relevant Apple ID doesn't exist any more, I had altered it when I had been asked repeatedly to confirm the contact e-mail which had expired much earlier. The domain that both the Apple ID name and the contact address had used don't exist any more. So now I can't even change the iCal's cloud connection. Cul-de-sac.

So this is my question: how do I get out of this cul-de-sac and how will I become able again to enter events into my iCal and have it mirrored in my iCloud calendar? (updating or renovating their accessibility for my wife will be a next step…)

Thanks for your help already!

Andreas