The agent is part of the Unsupported Appstore plugin. Installing it, will make installation and updates of the agent very easy. You can find the appstore here: https://forums.plex.tv/index.php/topic/151068-unsupported-app-store-as-in-totally-unsupported-is-currently-offline/
Alternatively you can install manually by downloading the zipped bundle from github, extract it, rename it to XBMCnfoTVImporter.bundle and copy it into the plex Plug-ins directory.
User MattJ from the plex forum reported the following steps to install on ubuntu 14.04:
- Download from github and unzip
- Remove "-master" from the end of both folder names.
- Copy them to the folder: /var/lib/plexmediaserver/Library/Application Support/Plex Media Server/Plug-ins
- Find the group number for user "plex" by command "id plex".
- "cd" to folder in step 3 and change ownership of both XBMC bundles: "sudo chown plex:{gid} XBMC*"
- run "sudo service plexmediaserver restart". Done.