We will update the OTA links as soon as they are available. Currently, the OnePlus 3T have received the OTA and full firmware file. The OnePlus 3 update may arrive late. So stay tuned.
Full ROM zip files-
How to Install Oxygen OS 4.0.2 onto OnePlus 3/3T?
In order to get the Oxygen OS 4.0.2 OTA update notification, the best option for you is to download the OTA via a VPN. This can be done by changing your device location to other countries like Germany or Canada where the OTA is currently rolling out. So download and install Opera VPN for that purpose and change the location to Germany or Canada. Then check for updates. See a full tutorial on how to use Opera VPN for OTA downloads.
The full ROM zip file can be flashed via TWRP recovery or using the very new Local Upgrade Android app method for the OnePlus 3/3T. The APK file will help you switch in between Oxygen OS 4.0.2, Open Beta, and Hydrogen OS without root or TWRP.
You can restore the device to complete stock. The OTA update can be installed via stock recovery using the options “Install from storage” or “Install via ADB” using the ADB sideload method.
Source: www.androidsage.com, OnePlus forum, XDA