Request upgrade to new security questions

Here’s how to change your security settings:

1. Sign in to your Apple ID account page.
2. In the Security section, click Edit.
3. If you already have security questions, you'll be asked to answer them before you continue. Forgot the answers?
4. Click Change Questions. If you need to set them up, click Add Security Questions.
5. Choose your new security questions, then enter the answers.
6. Add and verify a rescue email address.

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.

Source: Apple Support

Hopefully this helps :)