Acouple additional notes....
First - the recreate the old ID is virtually the only way to get this to work, but there are several issues with different devices onlg the way. But in my case, I was not able to use my old password because it did not meet the new requirements - this caused a whole slew of different issues!
On my iPad and iPhone - I also went to Messages and FaceTime, signed out of the old account and in on the new account.
To delete an iCloud account you FIRST habe to TURN OFF Fine My Phone!
On my iPad that was all I hade to do - it took the old id and the new password just fine, and I was able to delete the iCloud account.
However, on my iPhone that was not the case - it was still telling me that my password was incorrect...So form the Settings/iCloug screen - I tapped the old ID under ACCOUNT
The ild ID is there and greyed out and can not be changed, but the password can! I changed the password HERE to the new password assigned to the old ID and it verified perfictly.
I tried to turn off Find my Phone - and it fsiled again - but being a App Developer - I know sometimes it takes a couple of minutes for everything to sync - I tried it after 2 minutes and it finaly work! I was able to turn off FMP and then Delete the account.
And recreate an iCloud account with the new ID.
Food for thought - If your old account ID is tied to your iCloud account and you have purchased upgrades - I am not sure that those upgrades will be available in the new account. It does not look like iCloud actually changed ID's when you change your Apple ID - it lookes like these are not connected? I say this because I was able to log in with both the old ID and the new ID via the web and the new ID accoutn did not have any data in it untill I linked it to my first device - also I had to actually DELETE my old iCloud account from my devices to be allowed to log in with the new?
Confused yet - well... me too! Looks like Apple did not think this through very well!
Chris