Start by installing Google Authenticator on your new device.
Next, you’ll need your computer. Open Google’s 2-Step Verification page in a browser and log into your Google account when it asks you. In the “Authenticator app” section of the page, click “Change Phone.”
Choose the kind of phone you are migrating to and click “Next.” You should now see the “Set up Authenticator” screen, complete with barcode.
Open Google Authenticator on the new phone and follow the prompts to scan the barcode. Tap “Setup,” and then “Scan a Barcode.”
After the scan, you’ll want to enter the one-time code to verify it’s working.