As expected, Google has just posted the Android 6.0 Marshmallow factory images for the supported Nexus devices on Google developers page. As you know, Google announced Android 6.0 Marshmallow during the Nexus 5X and Nexus 6P launch event just a week back.
The latest Android 6.0 Marshmallow factory images for supported Nexus devices comes with build number MRA58K and is only available for following devices (The md5 checksum values for the factory images for those devices are listed too):
- Nexus 6 : 6f47aa1759670939e99d5cb0e3bc66a1
- Nexus Player : d96b17d325a1403168b34fe2a04d50cd
- Nexus 9 (LTE) : 5b85fa23d3f97cec6188b9db845d659b
- Nexus 9 (Wi-Fi) : aec68359986795636e72e53ad4f7a902
- Nexus 5 (GSM/LTE) : 159361223f975326fc261bb48def426b
- Nexus 7  (Wi-Fi) : 1d539755d74deef6811474fc1d4ec922
- Nexus 7  (Mobile) : 5c1458553b40f8cc9c2fd701b67cc133
As you can clearly see that the list doesn’t contain Nexus 4, as it is no more officially supported by Google and hence there won’t be any Android 6.0 Marshmallow update for Nexus 4. You can download the factory images from Google servers here. Make sure you download the exact file for your device.
Do not try to flash the factory image on any other devices except the device that is listed.
You can follow the steps given in our Guide to flash Android 5.1.0 on your supported Nexus device as the procedure to flash Android 6.0 Marshmallow is almost same as before. Flashing a factory image will erase all data on your device, so make sure to take a backup of your data before flashing the new firmware.
Always check the MD5 hash value of the downloaded file before flashing it. You can do so by using the free HashTab app for Windows explorer.