I did it this way:
- Save the document as web document (in german: „Datei als Webseite speichern…“. Dateityp: „Webseite, gefiltert (*.htm; *.html)“.
- you will get a html document and a bunch of pictures: Open the html file in a text editor, copy all html source
- paste the html source into the tool
http://www.dokuwiki.org/tips:htmltowiki
- now you have the wiki source
- zip the pictures into an archive
- upload the archive with the mediamanager (you need the plugin, which enables archive uploading and extraction)
- relink the pictures in the document