How to flash Official lineageOS on my non rooted CyanogenOS based ZUK Z1?

[AC Question]

I'm having a ZUK Z1 running CyanogenOS 12.1 and it's not rooted .Hence I really want to flash the Official LineageOS on my phone . Could anyone please give me a detailed information about it? How to flash Official lineageOS on my non rooted CyanogenOS based ZUK Z1?
Kindly give me some informations regarding Rooting ZUK Z1 properly and secure ,unlocking bootloader, and to flash the lineage OS . there is no information regarding about the installation of non rooted ZUK Z1 clearly in the internet.

 

[abdulbang]

I have also installed lineage os on my zuk z1. Its pretty simple.
First install adb drivers on your phone. When the phone is detected on the pc, unlock the bootloader and then install twrp recovery and from there install the os. As simple. For all the stages, u can follow youtube videos.