I bought a second hand xbox but it has a family passcode and I can't reach the previous...

My name is Fernando I'm an independent consultant, I'm happy to help.

To do this procedure, I need you to have access to the account linked to the console. Sign in with your console account.
Click the Xbox button on the controller to open the dashboard and select Profile & System > Settings > Account > Family Settings > Manage Family Members.
Enter a password or passkey to authorize the change.

I hope I helped and see you soon.

Bought Xbox 360 second hand and I don't know the family passcode or the answer to the security question. What do I do

Hi there.

Thank you for reaching out to the forum. Unfortunately a lot of people forget to factory reset their units before selling them, so you will have to contact support and they will walk you through the process of resetting your console.

• Support
  

Hope it all goes well, and you will be gaming in no time.

You'll need to contact support so they can give you a reset code. http://support.xbox.com/contact-us

I got this xbox as a hand me down and my brother cant remember the family passcode Or the secret anwser. I dont know what to do...

Since the controller was bought second hand, it could be possible the previous owner still has the controller register to his account. I believe you can only have a controller registered to one account.