It looks like this might be the command that is necessary. I'll try this out.
OS X or Linux
Open a Terminal window or your command prompt
Enter the following command (substituting the IP address of your server as appropriate):
ssh ip.address.of.server -L 8888:localhost:32400
Open a browser window
Type http://localhost:8888/web into the address bar
The browser will connect to the server as if it were local and load Plex Web App
Edit: I did this and got my plex working. Thanks for the link!