On your Mac/PC open iTunes (make sure it is updated). On the tabs on the left click on "iTunes Store". This will change the window on the right to the iTunes store. The top right corner should have your Apple ID or Sign In written. If there is an Apple ID written click on it and Sign Out. The corner should then change to "Sign In".
Now click on Sign In and sign in with the wrong/incorrect Apple ID that you no longer wish to use or update from.
Once logged in, click on the down arrow that shows when you move the pointer on the top right corner where it should now show the apple id, and select Account.
The page that opens up should have a section called "iTunes in the Cloud" with a tab on the side saying "Manage Devices".
Click on Manage Devices. Its should list your iPhone or iPad that you no longer wish to use with this Apple ID. And click Remove.
Once its confirmed click "Done" and from the top right corner select Sign Out.