I want to change the security questions and answers

If you want to change your Apple ID security questions, you can reset them from https://iforgot.apple.com/password/verify/appleid

https://support.apple.com/en-us/HT201485 

contact Apple ID Support. Based on multiple posts I have read, they may not be willing to help. See the Apple Support articles below for contact information.  

Apple ID - Official Apple Support.    

Contact Apple for help with Apple ID account security - Apple Support.   (Link doesn’t always load)  

Get Support          Work through the screens to get a chat option. 

Apple Support schedule phone call

https://twitter.com/AppleSupport.          People have posted it may take an hour or more to get a response.

From the Apple Support article below. 

Without proof of your identity via security questions and other carefully selected criteria, Apple Support can't help you reset a password or perform any other actions on your account. These policies are audited and reviewed on a regular basis.

Security and your Apple ID - Apple Support.      

See this document If your Apple ID is locked or disabled https://support.apple.com/en-us/HT204106 "If you or someone else enters your password, security questions, or other account information incorrectly too many times, your Apple ID automatically locks to protect your security and you can't sign in to any Apple services.

If you use two-factor authentication, you need a trusted device or trusted phone number to reset your Apple ID password and unlock your account. If you have a recovery key, you can also use it to help you regain access to your account. …

If you use security questions with your Apple ID, or if you don't have access to a trusted device or phone number, go to iforgot.apple.com. Then you can unlock your account with your existing password or reset your password. After multiple unsuccessful attempts to unlock your account, your Apple ID will remain locked and you can try again the next day.” Eventually you very likely will end up in account recovery.

Apple support might be able to help you if you have your receipt for the purchase of your device from an authorized Apple seller with its serial number on it. See the support options below. Alternatively, if an Apple Store is open in your area, then you can go there to deal with your problem. In this case, you can make a genius-bar appointment (https://www.apple.com/retail/geniusbar/) if you want.

Get Support: We’re here to help https://getsupport.apple.com/. Go through the options to find the best support option.; Apple Support Twitter https://twitter.com/AppleSupport; and Apple ID account security for country-specific and region-specific help https://support.apple.com/en-us/HT204169