I had a page with a css declaration on top and I moved it to another stylesheet, so my question is if I have to add a

HTML Code:
<LINK REL=StyleSheet HREF="mystyle.css" TYPE="text/css" MEDIA=screen>
to the place where the css styles where, what's the Zen way to do it?

I mean what functions I have to call, to replace that html?

That(the stylesheet mystyles.css), will be inside my template's css directory.