Il Mio Problema
I needed a new airport/Bluetooth Card an bracket.
La Mia Riparazione
It went without any difficulty just as the repair guide in the iFixit page.
Il Mio Consiglio
My advice is that you should not only buy the airport Bluetooth card, also buy the airport/Bluetooth bracket and the Airport/Bluetooth cable. With these you don't have to do any modification to the bracket of your MacBook.