The first method, and perhaps the way the general public is more familiar with, requires downloading the full tvOS beta software and restoring using iTunes. This method works, but it also means that everything that’s on the Apple TV, from settings to apps, will be wiped. You’re essentially setting the Apple TV back to factory defaults when using iTunes to update to the tvOS beta.
The more sensible approach is to use Apple Configurator 2, a Mac App Store app that can be used together with Configuration Profiles, to update to the latest tvOS beta.
The advantage of using the Configuration Profiles method is that all of your data, apps, and settings stay put. That way, you can enjoy all of the latest features of the tvOS beta, without having to go through the tedious initial setup process.
Note: you must be an Apple developer in order to take advantage of this method, because Configuration Profiles for tvOS can only be downloaded via Apple’s developer portal.
Step 1: Download the tvOS Configuration Profile from Apple’s developer portal
Step 2: Download Apple Configurator 2 from the Mac App Store
Step 3: Connect your Apple TV to your Mac using a USB-C cable. More details can be had about USB-C and the Apple TV in this post.
Step 4: Launch Apple Configurator 2
Step 5: In the All Devices view, drag and drop the tvOS Configuration Profile on the Apple TV image
Step 6: Once the profil has been added, Restart the Apple TV via Settings → System → Restart
Step 7: Update the Apple TV via Settings → System → Software Updates → Update Software
You will now see the beta update available for download
Step 8: Click Download and Install to begin the download process
Step 9: Once the download is completed, click Update Now to initiate the update
Step 10: Wait patiently as the update is applied. Afterwards, the Apple TV will reboot back to the Home screen
Once your Apple TV is back to the Home screen, you’ll notice that all of your apps and settings will be just as you left them. You’ll now be able to take advantage of the new features present in the beta without having to go back through initial setup, and without losing your data! Enjoy.