Q: How do I change my security questions?, How do I change my security questions?

You can only set up and/or change a Rescue Email Before you forget the questions/answers

For Forgotten Security Questions / Answers...

See Here > Apple ID: Contacting Apple for help with Apple ID account security

          Ask to speak with the Account Security Team...

Or Email Here  >  Apple  Support  iTunes Store  Contact

More Info >  Apple ID: All about Apple ID security questions