The Origami Forum

Here's the diagram:
http://www.origami.art.pl/show.php?id=3 ... F&dzial=PP

I am trying to fold the steps from 1 to 8, but i don't understand step 9.

Could someone please give me some hints?

In step 9 you should sink the parts you precreased in step 8.
If you don't know what a sink fold is, there's a .pdf file in the diagrams section of http://www.origami.com that explains all the basic folds and symbols.