How to update apple ID in iCloud settings

Question

Apple ID is greyed out, how to update apple ID in settings for iCloud on iPad mini?

Answer 1

If you want to move to a new, separate iCloud account you have to delete the account, create a new account with the other ID, and migrate your data to the new account.  Deleting the account will only delete it from your phone, not from iCloud.  This will not effect other devices still using the account.  Also, you can continue to share your ID for the iTunes and App stores even though you will have a different ID for iCloud.  They do not need to be the same.
To begin, if you have any photos in photo stream that are not in your camera roll or backed up somewhere else save these to your camera roll or you will lose them.  To do this, open the photo stream album in the thumbnail view, tap Edit, tap all the photos you want to save, tap Share, then tap Save to Camera Roll.
Once this is done, go to Settings>iCloud, scroll to the bottom and tap Delete Account. When prompted about what to do with the iCloud data, be sure to select Keep On My iPhone.  Next, set up a new iCloud account using a different Apple ID (if you don't have one, tap Get a Free Apple ID at the bottom).  Then turn iCloud data syncing for contacts, etc. back to On, and when prompted about merging with iCloud, choose Merge.  This will upload the data to the new account.
Finally, if you have any data in either iCloud account that you no longer want (such as someone else's contacts) you will then have to go to icloud.com on your computer and sign into each iCloud account separately and manually delete it.