How to install Android O Developer Preview on Nexus 5X, Nexus 6P, Pixel and Pixel XL
Installing Android O
Google deliver Android O Developer Preview just before their summer I/O event 2017. This Developer Preview is available for the Nexus 5X, Nexus 6P, Pixel, Pixel XL, Nexus TV and Pixel C. This is the first preview so its not very stable you will find some bugs and glitches here and there. So it mean this not for all users its only for the beta tester who like to see whats new in upcoming Android OS.
For installing Android O developer preview factory image you need your phone boot loader unlocked and the ADB tools installed on your computer. You make sure your device is visible to your computer to do that you go in Developer option and turned on ADB debugging. Then type "adb devices" in your terminal/cmd app, if you see your device listed you are ready to go.
Now you need to download Android O from Google factory image web site. After downloaded the .tgz file extract it. inside this .tgz file you find .zip file and you extract it too you find the boot loader, vendor image, radio image and a OS image.
Now run the script for installing Android O on your device. Make sure you backup all your data because in this process system wipe all the user data on the device so it is advice to backup your data manually before the installation began.
You turn off the device and start up device while holding the volume down and power keys together to boot into bootloader. Then connect your device to computer via data cable. Then go to command line to file directory with flash all script. Now run your script for MAC run "./flash-all.sh" and for Windows user run "flash-all.bat". Now you see the script running on screen its take some time you need to wait 10 min to finish it.
After the phone boot you have new Android O developer preview on your device. Enjoy