Hi Chris, we added ability in the jbpm web designer to import existing bpmn2 or json into the designer by selecting a file on your file system or pasting it into a form. This will be available in the next designer version..but for now yes, you could use the Guvnor Repository plugin in Eclipse to connect to your running Guvnor instance and upload the file, or in Guvnor select Create->New File, give it the name and bpmn2 format and then upload it via Guvnor alone.
Hope this helps.