Arrow [Q] KitKat Upgrade (D800)

Hello guys,
i have factory unlocked D800 and i have 2 question
1. how to upgrade to KitKat (i can`t perform it via Update Center cuz my device is not registered on AT&T)? i already have a OTA Update file in PC
Can be found here
2. update to KitKat can cause UNLOCK FAIL on my G2? as i mentioned below i have Factory unlocked, so if i upgrade it can`t work on any carrier?

Thanks in advanced