You need to remove the bumper. I found this link on how to remove bumper:
http://www.realtime.net/~rentner/Porsche/Radiator/Radiator.html
I also heard that Krylon black plastic spray paint is good for the faded plastic vents. I bought a can but I have not had time to work on it. If you do it soon, will you please post pics and advice? Thanks!