I changed my Apple ID on iTunes through my PC, and synced the PC with the iPad, iPhone and iPod. I can buy aps on the PC and sync them to the 3 devices, but cannot buy aps on any of the 3 devices directly. My old ID is assumed. How do I change ID on iP

Question

When I attempt to buy aps on an iDevice, my old ID is pre-posted.  Attempts to change ID requires my date of birth.  It won't accept my DOB, so I can not change from my old ID to my new ID.  How do I get by this roadblock, and buy aps on the 3 iDevices?  The 3 devices are iPod Touch, iPhone 4, New iPad 10.

Answer 1

Welcome to the Apple Community..
In order to change your Apple ID or password for your iCloud account on your iOS device, you need to delete the account from your iOS device first, then add it back using your updated details. (Settings > iCloud, scroll down and hit "Delete Account")
Providing you are simply updating your existing details and not changing to another account, when you delete your account, all the data that is synced with iCloud will also be deleted from the device (but not from iCloud), but will be synced back to your device when you login again.
In order to change your Apple ID or password for your iCloud account on your computer, you need to sign out of the account from your computer first, then sign back in using your updated details. (System Preferences > iCloud, click the sign out button)
In order to change your Apple ID or password for your iTunes account on your iOS device, you need to sign out from your iOS device first, then sign back in using your updated details. (Settings > iTunes & App store, scroll down and tap your ID)
If you are using iMessages or FaceTime, you will also need to log out and into your ID there too.