Once the proper configuration profile has been installed from the Apple Developer Center, the watchOS 4 beta can be downloaded through the dedicated Apple Watch app on the iPhone by going to General --> Software update.
To install the update, the Apple Watch must have 50 percent battery, it must be placed on the charger, and it must be in range of the iPhone.
watchOS 4 introduces three new watch faces, including a dedicated Siri watch face that displays dynamic information unique to each individual, new Disney-themed Toy Story watch faces starring Buzz Lightyear, Woody, and Jessie, and a Kaleidoscope watch face designed to turn static images into "mesmerizing patterns."
There are new complications for Now Playing and Apple News, and an enhanced Workout app. GymKit, a new technology platform, will allow the Apple Watch to interface with gym equipment for workout data sharing purposes, and Activity app will offer up intelligent coating and tailored encouragement, plus new monthly activity challenges.
A redesigned Music app syncs automatically with the Apple Music new Music Mix, and there are auto-sets for for swim workouts. There's also a new High Intensity Internal Training workout option, and the Apple Watch supports the new person-to-person Apple Pay feature.
watchOS 4 is only available to developers and will not be provided to public beta testers, so non-developers will need to wait until the software is officially released in the fall to try it out.