for those interested
Properties properties = new Properties();
PackageBuilderConfiguration cfg = new PackageBuilderConfiguration(properties);
KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder(cfg);
kbuilder.add(ResourceFactory.newFileResource("PATH_OF_YOUR_PKG"), ResourceType.PKG);
Collection<KnowledgePackage> pkgs = kbuilder.getKnowledgePackages();
for(KnowledgePackage pkg : pkgs){
for(org.drools.definition.process.Process proc:pkg.getProcesses()){
InputStream in = ((org.jbpm.process.core.Process) proc).getResource().getInputStream());
// Now you can serialize to a Dom element for example
}
}