Howto convert Openoffice to DocBook?

Hi all,

 

I want to convert documents from
open-office (*.odt-files) to the docbook-format (XML).

 

I’ve already heard about the
roundtrip-stylesheets but I can’t figure out how to use them for the
topic above.

 

Is there any help / hints out there.

 

I didn’t find any useful tips  in the
web :-(

 

Cheers

 

Robert