There can be multiple way to unlock iphone but depends on how much time you have to spent. If you have much time to spent on unlocking iphone then you can go through any way by searching over internet. If you are professional and don't have much time then it is best to use any third party service to unlock iphone. However, it is not free and requires some amount from you but it trusty and secure. Go to
Unlock iPhone for effective third party services.