Currently Being ModeratedJan 19, 2013 8:00 PM (in response to Youngkorea)
Only the carrier that the phone is locked to can unlock your phone. Apple does not unlock phones. Unfortunately per this document, SKT does not offer unlocking. In any case contact them, because sometimes policy changes and it is not always reflected in the document.
Currently Being ModeratedJan 19, 2013 8:02 PM (in response to FelipeV)
Sorry You need to contact KT, which is the carrier fo the phone you want to unlock?