Thanks for information Esteban.
I tried to put in my example above the URL: http://localhost:8180/guvnor-5.3.0.Final-jboss-as-7.0/rest/packages/defaultPackage/assets/myProcess/source .
And when I'm trying to start a process I got an Error: Exception in thread "main" java.lang.IllegalArgumentException: Unknown process ID: com.myProcess.bpmn (Even in the source I had this id: com.myProcess.bpmn):
<process processType="Private" isExecutable="true" id="com.myProcess.bpmn" name="Sample" tns:packageName="defaultPackage" tns:version="4" >
Do you know that is the problem?
Thanks for your help. I'm new in jBPM.