Its real Carbon Fibre. Im a complete novice and had never doen anything to a car before apart from drive it, and I managed it so I wouldnt worry too much...
Self tapping screws come with it (or should, they forgot mine) or they can be bought from Focus/B&Q. Its pretty easy, just drill at least 6 holes in the splitter spread out evenly (I used a little hand drill), tape the splitter to the car with masking tape to get the positioning right, then start screwing stright into the bodywork. I think Renault only use 4 screws on the original splitter and they can fall off easily, so at least 6 should do the trick, cost about £1 I think.
You cant really mess up as where you screw it in to the bodywork isnt visible to the outside. Ive got a few work in progress pictures I will find out for you in a minute.
And sure Chris you can have the old splitter, I believe it lives on the central reservation of the M1 as it fell off whilst on the motorway!