Running 2 (or more) instances of Jonas in the same Linux server

Hi,
I am running an instance of Jonas (JONAS_BASE, using the newjb command)  on a Linux (Redhat) server.

I would like to run a second instance of Jonas on the same server.
Of course I need to change the configuration because I am going to face numerous port conflicts otherwise (jmx, http, rmi, etc).

Is there a tutorial / a document / a page that lists all the modifications needed in the various configuration files in order to run a second
instance of Jonas ? And eventually a third ... etc ?

I have already asked the question in this forum but i am still stuck : 
http://www.developpez.net/forums/d1101461/java/serveurs-conteneurs-java-ee/jonas/faire-tourner-plusieurs-instances-jonas-simultanement-meme-machine/

It would be neat if you guys could provide a script that would modify all the configuration files whenever we want to add another instance of Jonas.

Thanks for helping.