Installing the tvOS 11 beta is more complex than an iOS or macOS beta, but it's also for developers only.
Apple hasn't announced a public beta for tvOS the way the company has for iOS and macOS. That means until it is released to everyone this fall, it's only available to developers. It also means installing it on the Apple TV (4th generation) is more complicated than a simple download and go. If you're a developer and you're having trouble getting the tvOS beta installed, here's what you need to do.
Unlike Apple's other operating systems, you can't back up your Apple TV; as such, Apple offers two options for updating tvOS: over the air, which just updates the system; and via USB-C, which restores the device to its factory settings.
How to install the tvOS 11 beta over-the-air How to install the tvOS 11 beta over USB-C
How to install the tvOS 11 beta over-the-air
A note, before we begin: "Over the air" is technically a bit of a misnomer, since you have to use a USB-C cable to initially connect your Apple TV to your Mac to install the tvOS configuration profile. That being said, once you've installed the configuration profile, you'll be able to wirelessly update your Apple TV to any subsequent beta versions.
Updating over the air only updates the system software; your configurations and apps should remain on your Apple TV as-is.
On your Mac, go to developer.apple.com/download. Enter your developer username and password to log in. Click on the blue Download button to the right of tvOS 11 beta configuration profile. Install the Apple Configurator app from the Mac App Store. Connect your Apple TV (4th generation) to AC power. Connect your Apple TV (4th generation) to your Mac using a USB-C cable. Launch Apple Configurator. Click on Add Profiles to your Apple TV and add the tvOS 11 beta configuration profile you downloaded previously. (Or simply drag and drop the file to the Apple TV icon.) Reboot your Apple TV once the configuration profile is installed. On your Apple TV, click on Settings. Click on System. Click on Software Update.
Your Apple TV should now detect tvOS 11 and download and install it just like any other update.
How to install the tvOS 11 beta over USB-C
If you prefer to wipe your Apple TV developer unit before updating, you can use the Restore Image option, which connects to your Mac via USB-C.
On your Mac, go to developer.apple.com/download. Enter your developer username and password to log in. Click on the blue Download button to the right of tvOS 11 restore image. Click on the blue Download button to the right of Xcode 9. Install Xcode 9 on your Mac. Connect your Apple TV (4th generation) to AC power. Connect your Apple TV (4th generation) to your Mac using a USB-C cable. Launch iTunes. Select your Apple TV when it appears in iTunes. Hold down the Option key and click on Check for Updates. Browse to and click on the tvOS 11 beta you downloaded in step 3.
Once iTunes has updated your Apple TV, hook it back up to your television and you're good to go.
Have you got tvOS 11 up and running on your Apple TV? Which method did you use and how did it work for you?
Update August 14, 2017: Apple has just released tvOS 11 beta 6 for developers. If you already have a tvOS 11 beta installed, proceed to System > Software Updates and download away. If you've been waiting for beta 6 to get started with tvOS 11, keep reading and we'll walk you through the set up!