Over-ride module css definition

Hi,

I fount that the tabs css is defined on the file:

<!--  the following styles were supplied from component module  -->
<!--  link style  -->
<link rel="stylesheet" type="text/css"
href="http://localhost/xaraya/modules/base/xarstyles/navtabs.css"
media="screen" />

but I want to make my own css definition. Is there a way to over-ride
this css writing a css file in a theme specific directory?

Thanks,

Bruno