how to transfer everything from one icloud to another icloud in same iphone
You cannot transfer everything from one Apple ID to another. 

Documents, photos, yes... apps, books, music etc, no.
The ID that purchased those [even free apps, even the iDevice itself] is locked to the Apple ID that purchased them &amp; can never be transferred. The only alternative would be to wipe all the old data &amp; set up as a new device, then repurchase the things belonging to the old ID. [This would also require the permission [password etc] of the ID giving up the device.

If all you really require is to change the email address associated with your ID, then you can do that - the ID itself is not dependant on any given email address [in fact it doesn't even have to be an email address, it's just easier to think that way]

See Apple KB : Change your Apple ID for full details.