In order to use this module.  You must first build it using maven 2:

  mvn clean install.

then the files:

  preferences/core/target/preference_core-1.0.jar
  preferences/core/target/preference_core-1.0.jar
  spring-remoting.jar (should be in your maven2, $HOME/.m2, repository)

must be copied into the geoserver libs directory ($GEOSERVER_HOME/webapps/geoserver/WEB_INF/lib/)

start geoserver

then you can query the preference module.

Example queries:
  (Sets the default value of the preference identified by string "key"to "defaultValue")
    http://localhost:8080/geoserver/wfs?service=wpss&request=setDefault&key=key&value=defaultValue
  (Gets the preference identified by string "key")
    http://localhost:8080/geoserver/wfs?service=wpss&request=getPreference&key=key
  (Sets the preference of the preference identified by string "key" to "newValue")
    http://localhost:8080/geoserver/wfs?service=wpss&request=setPreference&key=key&value=newValue