Did you read the docs?
http://docs.jboss.com/jbpm/v3.2/userguide/html_single/#configuration
-> public void deployProcessDefinition(ProcessDefinition processDefinition) {...}
Using that method and configuring the jBPM runtime to work with the database that you jboss instance is using, will deploy the process.
When you want to start a new instance of that process you need to be sure that all the required classes are inside the server classpath.
Cheers