How to Delete App Store Accounts in iTunes
If you're an iPhone, iPod or iPad user and want to delete your App Store account from the iTunes application, it's simple to do so. Your App Store account is the same as your iTunes Music Store account--that means the email address and password you use to sign into the iTunes Music Store is also used by the App Store. To remove your account from the App Store, all you have to do is sign out of your account in the iTunes program.
Start the iTunes application.
Click the "Store" option in the menu bar to open a drop down menu with several options.
Select the "Sign Out" option by clicking on it. iTunes will sign your account out of the iTunes store and will take you back to the store's home page. Signing out also removes your account from the iTunes application.