How to Install Android M Developer Preview on Nexus 5, 6, 9

Google announced Android M at Google I/O 2015. If you are adventurous user, can’t wait the official update, and would like to try out the new features of Android M, we will show you how to get Android M developer preview installed on your Nexus device easily in few steps.
Android M developer preview factory images are available right now only for Nexus 5, Nexus  6, Nexus 9 tablet, or Nexus Player.

Requirements:

• Nexus device with unlocked bootloader, read our guide on how to unlock your Nexus device bootloader, it doesn’t matter if your device is rooted or not.
• ADB and fastboot installed on your computer, read our guide to get adb and fastboot installed on your computer in few seconds.
• Android M Factory Image file for your device, download it from Android developer preview page.
• Google USB Driver installed on your computer and USB cable.

Please note that:
– Android M isn’t official, its a preview build for developers so you may find some bugs and its not recommended for daily use, install it on your device at your own risk.
– Be aware that this will wipe everything of your phone so backup your files before getting started, if you don’t want to lose your data follow our guide on how to get Android M installed on your Nexus device without losing data.

Steps:

1. Make sure your device is charged at least 30%.
2. Unzip the downloaded Android M ROM.tgz file and save it somewhere easy to find.
3. Transfer all files from the extracted folder to adb and fastboot directory.
   
4. Power off your device and wait until its fully powered off.
5. Press and hold Power + Volume down button until your device boot into bootloader mode, you can boot your device also into bootloader by following our guide on how to boot into bootloader, recovery, download mode using adb cmd.
   
6. Plug in your phone via USB cable to the computer.
7. Double click flash-all.bat to start flashing process, it will take a few minutes.
8. Don’t touch your device and wait until you see finished and your device reboot.
   
9. Once finish your device will stuck on boot animation for several minutes before starting up.

Enjoy the newest feature of Android M on your Nexus phone, if you want to downgrade to Android Lollipop or Android KitKat download the firmware from Nexus Factory Images page and follow the same steps to downgrade your device.