How to unlock someone else iphone

How is it locked?

• SIM locked to a carrier: Contact the carrier it is locked to and ask about their unlocking policy—>How to unlock your iPhone for use with a different carrier - Apple Support
• SIM PIN lock—>Contact your carrier for the SIM Personal Unlock Key (PUK) code
• Apple ID locked—>If your Apple ID is locked or disabled - Apple Support
• Locked in App Store—>If you see a message that says 'Your account has been disabled in the App Store and iTunes' - Apple Support
• Device Activation Locked—>Turn off Activation Lock - Apple Support
• Device disabled message —>If you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled - Apple Support