For step 2: I think you should have a look at the source file (view page source in your browser). The document you see is probably and XHTML (XML formatted HTML) document. It should have a URL tag, which lists your token.
In a normal browser (so not plex home theater) go to the details of a movie. Then you will see your token (I believe) in the URL, after where it says server.
Not sure if it is the token, but could be, since it is constant across libraries and movies.
Le token, c’est la partie de l’URL qui contient un code alphanumérique. Ca doit donner quelque chose comme ça: https://<addresse_ip>:32400/web/index.html#!/server/<token>/details/...