How can I change the details on my iCloud storage account.

Question

I recently changed my email address and as a result, my Apple ID. My storage account for iCloud still has the old address associated with it. How can I change this?

Answer 1

If the bottom line is that you now have a new icloud account and want to use it instead of the old account, you need to get the Apple data from the old account and put it into the new account.  (Note that this won't copy things like photos, instead sync them to a computer first.)
When connected to the account you want to GET data from, Go to Settings>iCloud and turn all data that is syncing with iCloud (contacts, calendars, etc.) to Off. 
When prompted choose to keep the data on the iPhone. 
After everything is turned off, scroll to the bottom and tap Delete Account.  Next, set up a new iCloud account using a different Apple ID and turn iCloud data syncing for contacts, etc. back to On.  When prompted, choose Merge.  This will upload the data to this new account.
Note that this only affects the "Apple data" like contacts, calendars, reminders, etc.  Many third party apps also use iCloud to store data files there.  These files may be lost in the process, unless the apps also keep the data locally on the device.