Factory images for the just released minor Nexus 7’s WiFi update that was given to the Android 4.3 build JSS15R is now available. Binaries have been made available too for your downloading and hacking pleasure.
You can download them from these links. Download them from where it says “Factory Images "razor" for Nexus 7 2013 (Wi-Fi)”.
Also check out how to Turn on Internet Sharing / Tethering / Hotspot on the Nexus 7 2013 LTE model.