Go setup yourself up to work with LArSoft as instructed at https://cdcvs.fnal.gov/redmine/projects/larsoftsvn/wiki.
Make yourself a test release in the usual way, newrel -t development dirname.
Now cd dirname and say svn co svn+ssh://firstname.lastname@example.org/cvs/projects/ubooneoffline/trunk/GENIEextractor, for example.
cd include; and say ln -s ../GENIEextractor/ . and cd back to the top dirname.
gmake GENIEextractor.all, and construct your fcl file and run lar -c myjobscript.fcl as usual.
Be sure and svn ci -m "helpful comment" svn+ssh://email@example.com/cvs/projects/ubooneoffline/trunk GENIEextractor and svn update svn+ssh://firstname.lastname@example.org/cvs/projects/ubooneoffline/trunk frequently.