IPHONE 5S activation unlock
 

hi, all members and viewers, regarding iphone 5s , me as a technician had recieved iphone5s for repair display 2 years ago, now customer had not come again to recieve his mobile, now i want to unlock that apple id and password, status of blacklist is clean,customer is also not in contact, now guide me what to do,pls help

If anybody can help in this task, please, help! Me joined to this instance.