8892 Views 1 Reply Latest reply: Sep 4, 2008 5:49 AM by neuroanatomist
In iTunes, select Store menu > Sign out. Then, select Store menu > Sign in and sign in using the new Apple ID. Then sync your iPhone - it will then be associated with the new Apple ID for iTunes music/app purchases.
If you're referring to the registration information you entered, there's no real need to change that - the Apple ID was used there only to easily populate your other information (address, email, etc.). (Apple's registration FAQ states, "Once you enter your information, your Apple ID saves you time when you make a purchase from the Apple Store or register a new product.") The only way to change the registration information is to reregister, which you can do using THIS LINK (though you really don't need to do that for your iPhone to keep working as it has been).
Hope this helps...