Apple released the second betas of watchOS 5 and tvOS 12 to developers. Both new betas come two weeks after the release of the initial betas, and one week after the release of a fixed watchOS 5 beta 1 that fixed an issue that bricked some Series 2 Apple Watch models.
Developers will need to have the proper configuration profile, which can be downloaded from the Apple Developer Center. Once the profile is installed, the beta can be downloaded using the dedicated “Watch” app on the iPhone by going to “General” -> “Software Update.”
The Apple Watch must have at least 50% battery remaining, and be placed on the charger and be in range of the iPhone. We would recommend strongly that this beta only be installed on devices other than your day-to-day device, as it is an early beta version.
The watchOS 5 update is compatible with Series 1, Series 2, and Series 3 Apple Watch models. It cannot be installed on first-generation “Series 0” Apple Watch models.
tvOS 12 Beta 2 is compatible with fourth and fifth-generation Apple TV devices, and can be downloaded onto the Apple TV via a profile that is installed using Xcode. Once that’s in place, new betas can be downloaded via the software update menu on the Apple TV.