re-flashing stock ROM question

[67defalt]

Hello,
I use LineageOS for 2y now, and I'm wondering if it's possible to flash stock rom again? I am a total noob about this, and I don't want to hard brick the phone.

I grabbed this zip file from Oneplus website:
https://www.oneplus.com/fr/support/softwareupgrade/details?code=PM1574156143164

Is this the whole system or just an update package? Do I also have to flash stock recovery or should I flash this directly with TWRP?

Thank you for your help and explanation.

 

[ocnbrze]

if you flash the stock rom, it can unroot the phone. i would just flash another custom rom. do you have a custom recovery (Twrp)? hopefully you made a nandroid backup before flashing lineage os. if you did you can easily flash back to stock that way.

i do not have your phone so i have no idea how OnePlus does their firmware updates.