[root]ASUS ZenFone3 Deluxe ZS550KL (Z018) WW_V24.40.140.33(Android N)for WW SKU only*

[xjunior]

I am not responsible for any damages done to your device after trying this little guide.

Prerequisite: Unlocked bootloader:
twrp-3.1.1-Z018-20170701 here: link
flash twrp with fastboot command: fastboot flash recovery twrp-3.1.1-Z018-20170701.img
download SuperSu and insert it into your sdcard: link
flash it, Wipe Cache/Dalvik reboot system , check if it worked with some root check app

 

[Ryder.]

Same way with other models. Just different recovery. It doesn't need wipe cache/dalvik (which is optional but i think that only flashing the zip is needed)

 

[ken2006i]

does this recovery work on ZS550KL CN?