Adding a class to secondary links

I have tryed everything to add a class named "shaun" to the secondary links I want them to use the css

#shaun {
padding: 0;
margin: 0;
line-height: 25px;
list-style: none;
background: url(images/primarylink_bg.png) repeat-x;
color: #000000;
}

But I can not figure out where to put my tags, i have tryed every page in my mind. But they never change.... Any ideas?