Locking rotation of dynamic physics object

I just tried to get the WIP plugin for integration of dyn4j with jme3 mentioned here working: Dyn4j integration
…unfortunately there is no documentation whatsoever and it also appears that it’s far from complete. How complicated is it to integrate dyn4j in a specific project from scratch? I am really interested in 2D-Physics for jme3 - for this and also future projects!
EDIT: Or DOES this plugin already work and i just don’t understand how to use it?