HTC has begun rolling out the Marshmallow update to all unlocked variants of its flagship smartphone, the One M9, located in Taiwan. However, the upgrade procedure is a little different to what you may expecting. Instead of installing one large update, owners will first have to download a 65MB preparation upgrade in order to tweak a few system settings, then they’ll have to download and install the Android 6.0 firmware.
To see if the update is ready for your device, ensure your unit has at least 50% charge, then head into Settings, scroll to the bottom and tap on “About Device”, hit “System Updates” and select “Check for updates”. Alternatively, you can wait until you receive a push notification prompting you to install the upgrade, but this will only happen if you’re connected to a Wi-Fi network.