Q: How to change iCloud username on iPhone 4S?

Go to Settings > iCloud > Account > Apple ID and change the AppleID as appropriate...but for iCloud the ID must be an email address.  If you had set the iCloud ID as an @me.com address then it cannot be changed.

Liane, have you read this knowledge base article to see if it helps?  Thre are restrictions on iCloud IDs and changes that you are premitted to make.  You may want to just go into Settings > iCloud and at the bottom of the screen Delete Account, then enter all of the new account information.

That is often the best solution, just delete from the device and reenter the correct information.

When you changed the AppleID, do you mean you changed the primary email address at the manage account section at https://appleid.apple.com/

Or, did you actually create a new AppleID with the outlook mail address?

If you did the latter, then you are fubar'd.  Your iCloud account's primary ID is the AppleID you used to create it, so if you created a new AppleID, your old one remains (regardless of the status of that primary email address) and so that iCloud account remains, and remains tied to that AppleID.

All you can do now is create a new iCloud account with the new AppleID.

As long as you just edit your AppleID information at the link I posted above, then you only change the identifier for that AppleID and the account itself is unchanged (so everything tied to that AppleID would work with the new login identifier).

If you changed it at the link, then you just need to delete the iCloud account and add it back with the updated indentifier. It will still be the same account, just there is no way to "refresh" an iCloud accounts login settings on the iPhone other than to remove and add-back the account.

Which has now come full circle to the second reply above...

And that is much appreciated, Liane...all fellow users on here trying to help each other with problems.  Hope you get this sorted out and working right for you very soon.

True, except as the op mentioned, I've never found you can actually edit the appleid under the iCloud account on my iPhone.  As far as I know, you have to actually delete the account, then add it back as a new account, but with the now changed identifier email address.  A bit of an obtuse way to accomplish a simple login edit, but it is what it is I guess.

icant remove icloud from my ipad because the old pasword doesnt work