Configuring the JCR-RMI extention is performed by the modification of a simple properties file (jcr-rmi.properties). The file is located in the source code tree at /extention/config/alfresco/extention/jcr-rmi.properties
The best way to override the JCR-RMI configuration is to put a properties file in the classpath before the jar which loads the extention /alfresco/extention/jcr-rmi.properties. This avoids the need to recompile the extention or the webclient package. This also ensure that the configuration alterations will persist between deployments.
Modification of war files either through explosion or recompiling for a given target is practiced by many but is inconsistent with the initial design goals of the technology. Overriding the configuration at the server is the best practice.
In tomcat this can be accomplished by putting the file (and folders) in the common/classes folder.
In tomcat this can be accomplished by putting the file (and folders) in the conf folder.