How to make your iPhone forgets someone else’s Apple ID
If your iPhone is asking for somebody else’s password, or if you have inherited an iPhone with somebody else’s account, your iPhone may keep asking for the password to the wrong Apple id. Here is a step by step guide, just follow it and you will get rid of that Apple ID and use your own.
1. Launch App Store.
2. An option “Featured” needs to be tapped.
3. Scroll down at the bottom, you will find the Apple ID.
4. Touch on that and sign out.
5. Hit Sign in.
6. Type in your own apple id password and touch Ok.