Users can install it via adb sideload or through a custom recovery
The new Android 4.3 Jelly Bean operating system has started to arrive on the latest Nexus handsets out there earlier this week, yet only as part of a staged process, which means that some users will receive it a bit later.However, the necessary update files are already up for manual download for some of these smartphones and tablets, including the Galaxy Nexus takju and yakju models, and those who would like to install the new OS flavor before Google sends it to them can do so now.
Available straight from Google’s servers, the Android 4.3 OTA update can be found on this page for the Galaxy Nexus takju, and via this link for the Galaxy Nexus yakju.
To upgrade their devices, Galaxy Nexus owners will need to have Android 4.2.2 JDQ39 running on them. Furthermore, as droid-life notes, they can use either the “adb sideload” command or a custom recovery to install the Android 4.3 update.