how do i reset my security questions
How do I reset my security questions on my Icloud account?
iPhone 6s Plus, iOS 9
If you forgot the answers to your Apple ID security questions - https://support.apple.com/HT201485
Kappy's user tip: Some Solutions for Resetting Forgotten Security Questions - https://discussions.apple.com/docs/DOC-4551
KingPenguin 02/2015 post - https://discussions.apple.com/message/27660375#27660375
If you still have problems:
Contact Apple for help with Apple ID account security - Apple Support - https://support.apple.com/HT204169