Go to Settings>iTunes and App Stores and sign out and sign i with the other ID
- Apps are locked to the account that purchased them.
- To update apps you have to sign into the account that purchased the apps. If you have apps that need updating purchased from more than one account you have to update them one at a time until the remaining apps were purchased from one account.
Also ther are some other places that are assocated with the ID:
SettingsMessages>Send and Receive