The following are simple steps to change the ORMI default port in Oracle Warehouse Builder.
Navigate to OWB_HOME\bin\win32 and run ccashut.bat(in case OC4J is already running).
Next navigate to OWB_HOME\owb\jrt\config\rmi.xml file look out for rmi-server tag for port and ssl-port attributes.
Change the default non-ssl port 23791 and ssl port 23943, to any port which is not blocked.
Now start OC4J by navigating to OWB_HOME\bin\win32 and run ccastart.bat.
Edit the ccashut.bat in OWB_HOME\bin\win32, look out for string ormi://localhost:23791 and change the port number here to the value you specified in rmi file, If this step is not done you cannot shutdown CCA.
After the above changes you have to un-register and re-register the Default Agent to make the mappings work.
Goto Control Center Manager
Right Click Default Agent
Select Unregister Option select Yes
Right Click again on Default Agent select Register
Change the Port here(the same port that was put in rmi.xml file) and Press Ok.
Note:- You might have to change the default ORMI port in cases where you have multiple versions of OWB, example on a development machine or you have two applications both running OC4J, for instance OBIEE and OWB both run OC4J and thus the best solution is to change the OC4J port for OWB.