Themes and .themerc files

I searched the archives for this and have not been able to find anything there
or other places on the web. Sorry if this is a stupid question and/or the wrong
place to ask this. 

I'm new to KDE having ignored "desktop envrionments" for years. I must say now
that I've taken the plunge I *love* it. 

There are several themes I've gotten from http://www.themes.org that I would
like to use with my KDE 3 install. According to the docs there anything 2.x or
better should have a .ktheme file. But the themes I've found so far from 2.x and
3.x all have .themerc files and no .ktheme files. I can not figure out how to
get the look and feel part of the control panel to see these themes as themes.
So how do I do this. In particular the theme that I want to use is the
Wintermute theme. 

Once again many thanks and sorry if this is the wrong place to ask this.