You can change your security questions if you knwo the current answers. if not, you will need to contact support:
Follow these steps:
All Products and Services > iTunes > iTunes Store > Account Management > iTunes Store account security
Answer the questions and if required sign in with your Apple ID and password - same one you used to log in on this support forum.
You will find an option to send an email to Apple on that page. Indicate that you forgot the answers to your security questions and wait for iTunes support to reply. Usually, you'll get a response after 24 hours.
Hope this is helpful =D