Installing the Android Marshmallow image takes a little command-line know-how. And as is the case with any pre-release software, you may encounter unforeseen problems, so install Android 6.0 on a secondary device that you don’t rely on, or be prepared to risk losing your data.
Getting startedSince installing the Marshmallow factory image will require you to wipe your phone, you’ll want to back it up before you begin. You’ll also want to update to the newest non-beta version of Android available—Android Lollipop 5.1.1 as of this writing—if you haven’t done so already. Updating now may save you headaches later on in this process.
Next, take a few minutes to download and install Google’s Android Studio developer tools if you don’t already have them installed. The installation process is pretty straightforward, and Google provides step-by-step instructions that explain how to do it. (If you don’t have Java installed on your computer, you’ll need to download and install that as well.)
Once you have the developer tools installed, go ahead and download the Android Marshmallow factory image from Google. Note that Google provides different preview builds for each device, so make sure you get the one made specifically for your device. You can get builds for the Nexus 5, Nexus 6, Nexus 9, and Nexus Player. The 2013 version of the Nexus 7 is supported, too.
Double-click the file you downloaded to unzip the image files. Keep these files in a safe place—we’ll come back to them in a few minutes.
Prepping your phoneInstalling Marshmallow requires you to turn on Developer Mode on your phone. The process varies slightly depending on the version of Android you’re running, but on Android Lollipop, pop open the Settings app, scroll down, then tap About Phone. Scroll down to the Build number and tap it 7 times to unlock the developer options.
Now return to the main Settings screen, then scroll down and tap Developer options. Finally, toggle the switch for USB debugging to the on position and confirm when requested.
On Windows, you’ll find the folder on your C drive. The filename path will look something like C:\adt-bundle-windows-x86_64-20131030\adt-bundle-windows-x86_64-20131030\sdk\platform-tools, though the names may vary slightly depending on which version of the developer tools you have installed. Your best bet may be to go to your C drive and poke around a bit.
Track down the image files you unzipped earlier, and move them to the folder containing adb and fastboot (it streamlines the process some by reducing the number of terminal commands you need to execute).
Now, we’ll make sure your computer can find your phone. Go ahead and plug your phone into your computer using a USB cable, and confirm the connection on your phone if prompted. To check for devices, open a Terminal or Command Prompt window (if you don’t know where to look, use your operating system’s search function to find the Terminal or Command Prompt).
cdfollowed by the filename path listed earlier into terminal then press enter—for example:
cdcommand is the same on both OS X and Windows; only the filename path format is different. Once you do that, type “adb devices” and press enter. You’ll see something like “
0ae33abd02ba3467 device.” If you see that (the big string of letters and numbers will vary), you’re good to go. If not, go back and make sure you have USB debugging enabled on your Android device.
(Note: If you’re using OS X and you get an
adb command not foundmessage, try adding “./” in front of the commands you type—for example,
./adb devices. This tells the Terminal to look in the current folder for the adb tool. This applies to all commands mentioned in this article.)
Once your setup passes the adb devices test, type
adb reboot bootloaderand press enter: Your phone will now reboot into fasboot mode.