Not sure what you mean by “map them to a new package”.
The easiest way to access custom java functionality is to create a java archive (jar) file containing your custom java classes and place that jar in the webMethods IS classpath by copying it into webm_home/IntegrationServer/lib/jars and restarting the server.
After restarting the server, create a new java service and add an import statement that references your custom package or a class in that package.
Mark
#Integration-Server-and-ESB#Flow-and-Java-services#webMethods