Using the new transfer feature. With your old and new iPhones powered on, unlocked and next to each other, your old phone should display a prompt asking if you want to set up a new phone. Tap. To prevent a thief from using your device, put it into "Lost Mode.". This will disable all notifications and alarms on it. Lost Mode also lets you write a message that will appear on the phone or tablet—for example, you could ask whoever finds it to return it and provide a phone number where you can be reached.
