decreasing depth of document structure

[Wolfgang Engelmann]

I use a Koma report style and would like to decrease the depth of its 
structure. It contains ONLY subsubsections
e.g 0.0.0.1 Vorwort
which I would like to appear as
1 Vorwort

the figures appear as 0.1 etc
which should appear as 1

How can I decrease the depth to achieve it?

Wolfgang