Trying to update to Gallery3 on my NAS

I'm a bit of a newb, so please bare with me. I just recently bought a D-Link ShareCenter NAS, wihch came with the Gallery software pre-installed. The version which is installed is Gallery2. I read about how Gallery3 is much better. I searched all over this website looking for clues on how to install gallery3 on my NAS...any ideas? Anything would be much appreciated.