As confirmed yesterday, Cyanogen Inc. has started to roll out official Cyanogen OS 13 (Android 6.0.1 Marshmallow) for OnePlus One and the OTA (over the air) update will reach on your device in coming days. If you cannot wait for the OTA update, you can download and install Cyanogen OS 13 manually. Read on to know how it is.
The official Cyanogen OS 13 (build number ZNH0EAS26M) for OnePlus One brings critical security fixes (security patch level March 1, 2016), improved stability & performance and new features to the device. You can enjoy Marshmallow’s native features like “Doze” battery saving, simplified app permission model, Cyanogen features like the new SMS app, new camera and more.
Note that Cyanogen OS 13 and CyanogenMod 13 are different firmware. Cyanogen OS is specially designed for OnePlus One (and other few devices) and it is official. CyanogenMod 13 is a custom ROM and community driven.
Cyanogen OS 13 (ZNH0EAS26M) for OnePlus One is an incremental update and it just weigh 508MB. To apply the update your device should be running on Cyanogen OS 12.1.
Download and Install Cyanogen OS 13 OTA update (ZNH0EAS26M) on OnePlus One
1. Download Cyanogen OS 13 OTA zip file [HERE] and copy the downloaded files in your phone memory.
2. Now, switch off your phone and boot into stock recovery (not TWRP recovery) by holding Volume UP + Power buttons together.
3. In recovery, select ‘Apply update’ menu. Use volume button for selection and power button for confirmation.
4. Go to the Cyanogen OS 13 OTA zip file, select and confirm the installation.
It will take few minutes to complete the flashing process. Once completed, reboot your phone and enjoy Android 6.0.1 Marshmallow. (Source)