Do a right click on the main project (one of the three projects mentioned above) → New → Other… (or press Ctrl + N). In the window, select Maven → Maven Module
Check the checkbox called "Create a simple project (skip Archetype selection)", give the project a "Module Name" and hit Next
Enter a human-readable name into the field "Name", fill in "Description" as needed
Click "Finish".
You will see the new project in the Eclipse Project Explorer. Now you can start creating or copying source files. Using the UTF-8 encoding is mandatory
Every .java file must contain the license header, starting in the first line. Be sure to have an empty line between the license and the package declaration.
The license has to look like this:
/*
* Copyright (C) 2012 denkbares GmbH
*
* This is free software; you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License as published by the Free
* Software Foundation; either version 3 of the License, or (at your option) any
* later version.
*
* This software is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
* details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this software; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA, or see the FSF
* site: http://www.fsf.org.
*/