You can get the system images/OTA files for Nexus and Pixel devices, but not all of them are actually October patches.
Google’s Pixel 2 and Pixel 2 XL are still only on the September security patch. All the downloads are marked as October builds, but the Pixel 2 and 2 XL are still on September patches after the update. Other phones are on October patch levels after this update.
It’s not clear why Google is dragging its feet on the Pixel 2 patches, or why they are still labeled as “Oct 2017” on the download pages. But this is the first time image and OTA downloads have been available for the new Pixel phones.
Read: Google investigating reports of Pixel 2 XL screen burn-in problems
To apply an OTA update image follow this link:
Google makes updated Android builds available for its devices every month, and the time has come for October’s downloads to go live for Google’s new phones.
The system images can be flashed onto your device even if you’re running unofficial software. However, you need an unlocked bootloader to use them. The OTA files will work on a phone with a locked bootloader, though.