I changed a user's account on the server from say user@domain1.com to resu@domain2.com

I changed their isync details to the new account.

All their calendar entries now are showing up fine, but they say they were organized by user@domain1.com, and we cannot edit them!

So how do I change all the appoints created by user to resu?

Or other suggestions, other than spending hours going through each birthday, re-occuring appt, and everything and re-creating them!?

I appreciate any tips and advice. Thanks!