If you have enrolled in two factor authentication longer then 2 weeks ago, there is no way to disable it
If you have two step verification instead of two factor authentication you can turn it off follow these steps
- Sign in to appleid.apple.com.
- In the Sign-In and Security section, click Account Security.
- Click Turn Off two-step verification. Click again to confirm.
- Create new security questions and verify your date of birth.
You'll get an email confirming that two-step verification for your Apple ID is off.