If you've been wondering how the Pixel phones will compare the Nexus line when it comes to updates and images and all things open-ish, you'll be happy to know that Google has posted the latest factory images and the day-one OTA update images at the Android developers site.
Three builds are available as a full image as well as incremental zip files (OTA updates), NDE63H, NDE63L, and NDE63P. All builds are Android 7.1. You flash things the same way you would have done on a Nexus phone or tablet, and we have a set of instructions here to make it as pain-free as possible.
Of course, you'll always be able to find more help in the forums which are filled with folks who love to flash ... anything. It's just fun!
You'll find the images and OTA files at the links below.