Share your experience!
Can i make a local update?
I'm not quite sure I understand your question. You will need some kind of Internet connection to update your device.
It can be through Wi-Fi or cellular data if you update directly in your device by going to: Settings > About phone > Software update
You can also update you device by downloading Xperia Companion to your PC or Mac. Your computer will need to be connected to the Internet for you to be able to update your device.
Let me know how it goes, or if misunderstood your question.