Tutorial: Install LineageOS 14.1 (Nougat) on Verizon HTC 10

Now that LineageOS pre-official nightlies are available for the HTC 10, I thought I'd take it for a test drive...

WARNING: THE FOLLOWING GUIDE IS ONLY FOR U.S. VERIZON WIRELESS HTC 10 SMARTPHONES (VZW pme).  I CANNOT BE HELD RESPONSIBLE FOR ANYTHING THAT GOES WRONG IN THE PROCESS OF FOLLOWING THIS TUTORIAL.  USING YOUR DEVICE IN THE WAYS DESCRIBED BELOW WILL VOID YOUR WARRANTY.  PROCEED AT YOUR OWN RISK.

0. Important: this process will wipe your internal storage so transfer all desired settings and files to your external SD card or PC beforehand!

1. To ensure you have the latest official Verizon firmware, make sure your HTC 10 is fully up to date (Settings > Software updates > Check now).  If the OTA update via your phone fails, you can also update using the HTC Sync Manager wizard (recommended) or manually by downloading the latest Verizon HTC 10 RUU zip file here and following the instructions for installing it here.

2. Gain root access (similar to "jailbreak" on iOS devices) and install the latest TWRP recovery by following this guide.

3. Copy the latest LineageOS image onto the phone's external SD card.

4. Copy your preferred variant of GAPPS 7.1 ARM64 onto your external SD card -- I like the micro version but you can pick the one that best suits you (...and yes, this step is required).

5. Charge your phone to 100%

6. Boot into TWRP recovery by holding the Volume-down and Power keys simultaneously until the device powers off (about 15 seconds) and then remove finger from power key as soon as it powers off but keep pressing Volume-down until the boot menu appears.  Press the Volume-down key multiple times until "reboot to bootloader" is selected and then press the Power key.  Press the Volume-down key multiple times until "BOOT TO RECOVERY MODE" is selected and then press the Power key.

7. Create a full nandroid backup

8. After the backup completes, in the TWRP menu choose "Mount" and uncheck "System" if it is checked

9. From the TWRP menu, press "Wipe" and Swipe to Factory Reset

10. Press "Back"

11. Press "Format Data", type yes and press the blue checkmark button on the screen keyboard to continue (note: this step will NOT wipe your external SD card contents)

12. Press the home icon (house-shaped icon at the bottom of the screen)

13. Press "Reboot"

14. Press "Recovery"

15. On the TWRP menu choose "Install" and select the zip of LineageOS, then press "Add more Zips" and select the zip of GAPPS.  Swipe to confirm Flash (note: if you see "E:unknown command [log]" in red twice during the flash process you can safely ignore it; when the process completes you should see "done").

16. Press the "Wipe cache/dalvik" button and Swipe to Wipe

17. Press the "Reboot System" button

18. It will take about 5 minutes upon first boot so be patient if it just displays the generic "android" screen for a while...

19. After your phone boots, follow the wizard prompts and then go to "Settings > About" to verify the version.

Enjoy!

Credit: crpalmer, misterk267, and vahid-hetfield