Choose the relevant pet from the My Pets home screen. From the bottom navigation bar, select "Profile" and scroll down to "Replace Tag". Be sure to do the process away from any other Pawscout tags or Bluetooth devices. Follow the directions in the Pawscout Setup Wizard.
If your new tag stops halfway through the syncing process, go to your settings from the My Pets screen, and select Contact Support. By sending us an email, it can help us determine a solution to your app and tag not syncing.