In OpenOffice Writer 3.2, I try to change the numbering style used for Heading 2, but in the Outline & Numbering tab of the Paragraph Style dialog box, the Numbering Style option is greyed out. I have no clue why, and OpenOffice doesn't give any hints why this is so either, nor in the dialog box, nor in the associated help page.
So, how do I change the Numbering Style associated with Heading 2?
(I am pretty fluent in using Word's styles and numbering, but I have to say that OpenOffice's implementation of numbering styles isn't very intuitive to me).