If anyone is still interested in this...
The original install disk (aka "enclosure disk") installs the software, version 2472.518, which is dated 2010. There are "firmware" updates to original install, versions 2572.572 and 2672.625, which fix some things and make some improvements. These two are ".bin" files and use the "firmware update" option on the LG-NAS GUI when using a browser to talk directly to the NAS at it's IP address. The "firmware" gets updated, but your data remains intact (but I would backup your data just to be careful.)
There is another set of updates that begins with an update called "New User Interface Firmware NS2 B2B Common 10072", aka Version 10072 (new nomenclature). When you open that .zip file, it contains a text file with installation instructions and an ".iso" file, that you must create a bootable CD-ROM from the image file (not just copy the .iso file to a CD-ROM). There are two follow-on "firmware" updates (10119 and 10124), but they are ".bin" files. 10124 is dated 2015 and is the last firmware update that I am aware of.
First: YOU MUST BACKUP YOUR DATA OR YOU WILL LOSE IT. 10072 reformats the hard drives.
To install 10072 and the new GUI / UI, the system initializes like the initial install (power up while depressing the "S" button on the front) including reformatting the hard drives.
It has a new user interface and you lose some capability, but I believe it installs a newer version of the Linux operating system (a file on the new install disk says "Ubuntu 9.10 Karmic Koala").
My hypothesis, which I will check in a month (or so) when I save up enough to buy 4 more 2TB hard drives, is that you could skip the initial install (2472.518), and boot/install right to version 10072, then the two "minor" (.bin) updates. Specifically, I speculate that you don't need to track down a copy of the original install disk / enclosure disk to get started. All you need to do is download the New UI / 10072 "firmware update" , cut the CD-ROM, and install directly.