How to reset Calendar and Reminders on OS X Yosemite?
I would say, you're off the wrong foot deleting files in ~/Library since the storage there changes from version to version (and sometimes even build to build).

If I have AppleCare - I just call them and they have internal documents and the ability to get you the exact steps for your exact situation.

If I don't want to call Apple or I have time to work on the issue - Here's the strategy I've employed to clean things out when iCloud is messed up. It takes me far less time to do it this way. :-)


Make a new account on your Mac
Log into iCloud.com and check if the cloud "truth" is correct.
If it is, sync one bucket of data to the new account. (Calendars)
If it's correct, turn that bucket off and let it delete all the local data if it prompts you.
Repeat the "sync one bucket" until you've checked all the buckets you wish to be correct.


If there were issues syncing one bucket - contact Apple Support or install a new OS and re-test on the new OS.

If there are no issues - then turn on all of the buckets in the new account to verify things are OK.

At that point, you know these things:


iCloud has good data
Your Mac has good software
The settings you want will work


At that point, you can make a decision to migrate the user from the broken user (it might be broken from you deleting things or a bug or just bad luck - but it's clearly broken).

If you really want to clear things out, it would be best to just ask separately. The steps to clear Calendar are not the same as clearing Reminders.

Also keep in mind - other devices can inject data into the cloud - you might have to isolate the problematic Mac and the Cloud data in some cases.