Is it possible to apply document defaults

[racoon]

Hi

I know of the "Save as Document Defaults" in the document settings. What 
it seems to do is create a default document with preferences that is 
loaded when one creates a new document.

However, if I have created a number of documents using those defaults 
and discover that I would like to have something differently, is it 
possible not only to save the new settings to the defaults for new 
documents but also apply those defaults withing other already existing 
documents?

I guess I am missing an "Apply Document Defaults" button in settings. 
But maybe there is a different way in LyX to do this.

Best,
Daniel