My iPhone 5 is accidentally blocked. How do I unblock it?

[iMore Question]

Hello,
My son decided to change his pin number (whilst slightly drunk) and he can't remember the number, so he cant use his phone.
He can receive incoming calls only.
The screen message tells him to connect to iTunes !
any advice will be gratefully received,
thanks

 

[kch50428]

https://support.apple.com/en-us/HT204306

 

[Just_Me_D]

In addition to the above link, check out the information via the following link.

https://support.apple.com/en-us/HT201529