Pretty much most days I am the person who is taking a design from a designer and reimplementing that in HTML/CSS. I couldn't tell you where to start when creating a design, but as far as taking something someone else has created and reimplementing it in code? I can do that all day long.
The visual guidelines PDF exists http://interface.free.fr/Archives/GUI_Xp.pdf and turning that into a web page is just a matter of creating some DOM elements with the right sizing, margins, padding, fonts, borders, etc.