changing an existing Aras 12 installation


I wanted to install a second instance and code tree of Aras innovator12, like to have a dev server and a test server, so I followed the instructions to run changeGUID and indeed got the possibility to install a new instance of innovator with innovatorsetup

how do I edit the existing instance as we now have a problem with it, I tried to run the original installer and it took me to the new instance? I tried to run changeGUID again but it  still took me to the new installation?

thanks for any help or point to further documentation 

Mark Norris