check this out:
http://gogulea.home.ro/
it is a printscreen from the C-MAX user guide.
However, remember that there are3 security things related to a remote key:
-the mechanical part (the shape of the key); there are o lot of places where they can modify mechanicaly the key to fit your lock; you will need aworking key too
-theradio code of the key; you have above instructions about how to modify this
-the security chip inside the key, that can unlock the immobilizer of your car, so you can start the engine; as far as I know, you can change this only in a dealer workshop.
so, if what I know is true, then you can program by yourself a new key only to open the car, not to start the engine