From cyanogenmod to oxygen OS - need your help

Hello everyone,

I'm currently on the latest 'stable' cyanogenmod custom rom (cm-12.1-20150901-SNAPSHOT-YOG4PAO236-bacon.zip)
Now I want to switch to the latest oxygen OS version.
I found on the official site the 1.0.0 Version as a zip file.
I wantes to flash it via twrp - but it fails every time.
Does anyone got a real noob friendly tutorial how to switch from cyanogenmod to oxygen os?