Were the filename is the link you just copied from Plex. Now we need to download the update, copy the url from the plex website, as of today that would be now in your ssh terminal type the following wget I download mine into /home/install using this example the code would be. Now we need to navigate to a directory that the update can be downloaded into. Where USER is the user of your media server and SERVERADDRESS is the IP or domain name of your media server. If there is then it's time to ssh into your media server. Now check the Plex website to see if there is a newer version available for Cent OS. To see which version of Plex you are running simply log into your web interface for your media server and go to Settings > Server > General you will see something similar to the screenshot below. This little guide will go through the process of ssh'ing into your media server, downloading the latest version and then manually installing it. I've been using Plex Media Server now for nearly a year and unfortunately if you run the system through Cent OS command line there is no automatic way of updating it.

Whatbox plex media server update