How to achieve a basic setup of LineageOS with root and Google Assistant?
So this is actually pretty easy if you phone is already unlocked.


Boot into recovery mode
Wipe the phone.  I advise going under advanced and checking everything unless you have files you need.


I wipe everything including internal storage but you don't have to 
Install the zips starting with LineageOS, SU addon, Google Apps/Google Play Store &amp; Google Voice Assistant.  You should not reboot your device until all are installed.
Reboot you device out of recovery mode and go through the set up menus.