You have a ReadiBand already, but it looks like you need to replace it. Follow the instructions below to unpair your old ReadiBand and pair a new one.
What you need:
a new ReadiBand
the Readi mobile app
How to unpair your old ReadiBand
Tap Sleep Tracking Device
Tap Unpair and follow the prompts to unpair your old ReadiBand
How to pair your new ReadiBand
Step 1: Tap the orange banner at the bottom of your screen.
Step 2: Enter the serial number found on the underside of your new ReadiBand