So sad to hear that Samsung Galaxy Note 3 and Google Nexus 7 from 2012 were not included in the list of devices that are to receive the update facility. However, with ingenious developers’ efforts, nothing is impossible as they have come up with Custom ROM for the devices and have enabled users to enjoy the perks of Android 6.0 Marshmallow.
Let us first discuss Google Nexus 7as its users can use AOSP (Android Open Source Project) 6.0 Marshmallow online. Kudos to vocoderism that is XDA Developer Forum’s senior member and the magnificent AOSP solution is wholly and solely dedicated to this champ’s amazing work.
As far as Galaxy Note 3 is concerned, this time again, the talented XDA Developer Forum member named Morningstar came to rescue. The amazing solution has been made available through CyanogenMod CM13 series that is a custom ROM to the Galaxy Note 3 LTE model. This ingenious solution would make the device fit for the Android 6.0 Marshmallow update.
As far as the update download is concerned, you can visit XDA Developers Forum official site and download the link. Follow the directions that will lead you to the Marshmallow update on both of these devices irrespective of which one do you use.