If you have 2FA enabled on your device, and are forced to switch it onto a new device, stress not - the process is simple and outlined below.
Step 1: Disable 2FA using your old phone
Access your Bitfinex account and navigate towards the Security section. Expand the Two-factor Authentication settings on your account and Disable it, as seen below:
Step 2: Confirm disabling of 2FA via email
You will receive an email asking you to confirm your actions. No changes will be made to your account unless you confirm the email.
Step 3: Enable 2FA on your new device
Using your new device, set up 2FA on your Bitfinex account as you normally would. A precise guide on how to go about doing this can be found here.
We strongly recommend that you go through the steps listed above in quick succession, minimising the amount of time that your account is without 2FA.
If you have lost access to your primary 2FA device, please contact Bitfinex Support to have the issue fixed.