Asus Released Android M for Zenfone MAX ZC550KL.
-some application improvement,with a mark for energy saver.
Usualy if it's a mistake or bad behaviour,Asus make a fast "fix".
1. Software update to Android 6.0 Marshmallow. Internal storage will decrease slightly after updating, suggest to backup data and relocate media files( pictures & video clip ) to SD card to reserve enough space before starting the software update.
2. Android Marshmallow won't support APP2SD. Please move apps to internal storage before the system upgrade.
3. Multi-user function won't be supported if the account is deleted, Please keep your account to continue using.
an assist feature has been added.
Download Link to Official Android M Update file = Click Here to Download
You can go to menu and updates to update via OTA or
1. Download the file
2. Place in SDcard
3. After removing usb cable you will find notification
4. Click on that notification then press on ok and you phone will automatically install the New Android M. The file is totally untouched and orignal. It will take upto 30-40 Minute to install your new OS in your device..
5. Make a Hard reset to get device run smoother with new OS.
You can see this video tutorial on Installing the OS.