if I understand your question, you have set up WAS to use some credential as it's PrimaryAdmin ID and now you need to change its password? or are you referring to the credential that runs WAS at the OS level. If the first, I suggest you check all of your *.props files make sure you re-encrypt them after changing. The change is disruptive so you will need to restart the cell and other JVMs. If it's the credential that runs the WAS process, if on AIX/Linux changing the password does not impact WAS because it does not save or cache the id's password. It should be trasnparent.