These tutorials are PDF documents. Acrobat Reader version 5.0 or higher is required to read them - you can get the free Acrobat Reader on the Adobe Homepage. You may either download the tutorials or read them online.
Please note that the tutorials are only available in German yet. Translating tutorials into a language which is not your mother tongue is a tricky job - whereas two or more mistakes don't really matter in passages like this as long as you get the point, they may cause a lot of damage in tutorials dealing with difficult subjects such as hacking. So please be patient - all tutorials _will_ be translated, promised :-).