How to Unblock an iPhone Without Having to Put a Passcode in It
With an iPhone device, you have the option of adding a four-digit passcode to lock your phone while not in use, which is useful for protecting your privacy and against theft. After typing the passcode incorrectly multiple times, the iPhone will become disabled. You can reset the passcode and re-enable your device by restoring it to factory settings using iTunes.
Turn off the iPhone.
Open iTunes. Plug the correct end of the USB cord into your computer.
Press and hold the "Home" button located below the screen on the iPhone while plugging the USB cable into the phone. Keep pressing the "Home" button until the screen shows a USB cord, the iTunes logo and an arrow pointing to the logo. iTunes will say your phone is in "recovery mode."
Click "OK" on iTunes.
Select "Restore and Update," then "I Agree" when the license agreement opens.