Though Google discontinued Nexus Player for future software update, its owners can still taste the flavor of Google’s latest OS with custom ROM like Lineage OS. First official nightly build of LineageOS 15.1, which is based on Android 8.1, has been released for Nexus Player (code named fugu). Almost all aspects of the ROM are working as expected, except few not working issues with Netflix and Google Play Movies.
Back in November 2017, Google updated the Nexus Player to Android 8.0 Oreo, but now Google confirmed that the device will not get further software updates, including security updates. However, with custom ROM like Lineage OS, its users can taste flavors of Google latest Android OS.
LineageOS 15.1 for Nexus Player brings a taste of Google’s chocolate-milk cookie-flavored OS, Android 8.1 Oreo. If you are interested, you can download and flash the official LineageOS 15.1 build right now.
Note: To install this build, your Nexus Player should be running on stock Android 8.0.0 (OPR2.170623.027, Nov 2017).
As you all know, installing custom ROM requires unlocked bootloader and custom recovery like TWRP installed on the device.
Installation Instruction
1. Download LineageOS 15.1 for Nexus Player (code named fugu) from here to your device.
2. Download TV Gapps from here to your device (Gapps for smartphone won’t work with Nexus player).
3. Boot your device into TWRP.
4. Choose Wipe > Advanced Wipe > and then Wipe Data, Cache, Dalvik-Cache, and System.
5. Choose Install and install LineageOS 15.1.zip weekly build.
6. Once again choose ‘Install’ and flash Gappz.zip file also.
7. Finally, select Reboot > System. Your device will boot into your new OS. Enjoy! [Source]