I assume that you have checkout out EPF source code into Eclipse workbench
and modified "publishing" plugin. If that's the case, you could just use
Eclipse Export->Plug-in Development->Deployable Plug-in and framgments.
Choose whichever plugin you want, export as JAR file. You can drop that
jar file on your regular EPF jar file. And start using it. This is
standard way of exporting plugins/building jars. If you need more
information, you should be able to get that from main Eclipse site.