From the Beam Dental app, tap on the three lines in the corner to open the menu. Select the option for ‘Set up a Brush'. With your new brush powered on and nearby, follow the steps to sync it to your account and the desired member of your policy.
By adding the new brush to the profile of the person whose brush was replaced, it will unsync the old one and add the new one!
If you encounter any issues, select the ‘I can’t find my brush’ link and follow the troubleshooting steps.