Unlock bootloader.
Flash twrp via fastboot. (Hold vol up when reboot for first time, then it should boot to twrp, choose language english)
Flash rom kenzo 6.3.31 via twrp or updater app.
Wipe cache, dalvik cache, reboot.
Flash supersu zip.
Done!
Xposed: use version Miui edition by Solarwarez...