You could use 'diff' or something similar to find out what's changed and put just those lines of CSS in a file in your theme folder.  Generally, I find the best way to avoid this problem is not to get into it in the first place by keeping the custom CSS in the theme folder to begin with.  :)

Brian

On Wed, Dec 22, 2010 at 5:52 PM, Marty Landman <mlandman@face2interface.com> wrote:
I've upgraded a D5 website for a client and the CSS files for
nice_menus had been customized within the nice_menus module's
directory, which obviously got overwritten by my upgrade.

Which I understand is why this wasn't the right way to do things. I'm
sure that copying the old css files fixes the problems, because I
did. Want to do things according to best practice. I could just take
those entire css file contents and append them to the style.css file
for the theme. That'd work I think, but is there a better way, w/o
actually picking all the lines apart to see what's needed?

Marty

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