Change your Apple ID security questions
If you haven't upgraded your Apple ID to two-factor authentication, your account will use security questions to help keep it secure. Follow these steps to change your Apple ID security questions.
About Apple ID security questions
Two-factor authentication is the most secure way to protect your Apple ID. If you haven't set up two-factor authentication for your account, Apple uses security questions to provide you with a secondary method to identify yourself online. Security questions are designed to be memorable to you, but hard for anyone else to guess. When used in conjunction with other identifying information, they help verify that you're the person requesting access to your account.
You may be asked to answer one or more of your security questions before you can change your password or other account information, view your device details, or make an iTunes or App Store purchase from a new device.
If you don't want security questions or you're concerned about forgetting the answers, you can set up two-factor authentication. Find out about two-factor authentication.
Change your security questions
Sign in to appleid.apple.com.
In the Sign-In and Security section, select Account Security.
Under Security questions, select Change security questions.
Choose your new security questions and their answers, then select Update.
Enter your Apple ID password, then select Done.
It's very important to remember the answers to your security questions to avoid being locked out of your account. And make sure you add and verify your rescue email address. If you forget the answers to your security questions, you'll need a rescue email address to help you reset them. Find out what to do if you've forgotten the answers to your security questions.