How do I get an iPhone 4s out of blocked mode?

[iMore Question]

How to get an iphone 4s out of blocked mode

About a week ago my dad's iphone 4s went to diabled mode. He has recieved several iphone found message although the iphone isn't lost. He tried reseting it using itunes and today in the itune process he was asked if he wanted to continue or cancel. He hit continue and it went to iphone block mode.

How can i help him fix it?!

 

[Ledsteplin]

He will need to restore the phone through iTunes. He will lose all his data, including photos. There's no other way I don't think. He will need his Apple ID and password to set up afterwards.
Forgot Passcode
https://support.apple.com/en-ca/HT204306