Have you ever made the mistake of forgetting your OC4J administrative password when installing OBIEE? It's happened to many of us and here is a great solution originally from David Kwan that can help you reset your password in a few minutes. I can't claim this as my own but have used this several times to help clients recover from any non-documented installs of OBIEE on their servers.
So here's the secret from Oracle Technical Support to reset it.
Please use following steps to reset your password:
1. Navigate to the <oc4j_root>/j2ee/home/config directory
2. Backup the file: system-jazn-data.xml for restore or later reference
3. Edit the file: system-jazn-data.xml
Locate the following entries:
<user><name>oc4jadmin</name><display-name>OC4J Administrator</display-name><description>OC4J Administrator</description><credentials>{903} MMGWnYKcnMKBBOR1LroHHrQpy3zmVbGEohN4aUSjxK4=</credentials></user>
and add the XML attribute deactivated="true", as shown below:
<user deactivated="true"><name>oc4jadmin</name><display-name>OC4J Administrator</display-name><description>OC4J Administrator</description><credentials>{903} MMGWnYKcnMKBBOR1LroHHrQpy3zmVbGEohN4aUSjxK4=</credentials></user>
When you next start the oc4j instance using "oc4j -start" the container will re-prompt you for the password and add the newly encrypted password to the <credentials> tag in the oc4jadmin entry.