Great models!
You are only asking for skinning, but I fear that they don't have a uv-map yet, too.
So, these are two jobs that have to be done, or did the modeler already layout the skin while building the model??

http://www.puppenheim.org/
http://www.wuerfels-welt.de
Old Game Tutorial: http://www.puppenheim.org/MITutorial.zip
Free Game Editor: http://puppenheim.org/AlienalsWeihnachtsmann.zip
http://www.puppenheim.org/blender_starting_main_settings.txt