Google started to roll out the Android N Developer Preview 5 (build number NPD90G) OTA update for supported devices and if you are already running the previous Developer Preview, you will get the OTA update on your device. As usual, Developer Preview 5 is available on Nexus 5X, Nexus 6, Nexus 6P, Nexus 9, Nexus Player, Pixel C, and General Mobile 4G (Android One).
Below are the some of the new changes of Android N Developer Preview 5 You can see all the new changes, known issues, bug fixes and features of Android N Developer Preview 5 (NPD90G) update in this page. – An emulator that you can use for doing the final testing of your apps to make sure they’re ready – The final N APIs (API level 24) and latest system behaviors and UI – The latest bug fixes and optimizations across the system and in preinstalled apps As mentioned above, this is the final preview build of Android N and the final build of the Android 7.0 Nougat will be released in October (most probably). Download and Installation Instruction for Android Nougat DP5 If you have opted for Android Beta program, you will get the OTA (over the air) for the new update. New users can download the Android N DP5 factory image [HERE] and flash it manually. (Source)