Hi, I’ve had an FP6 for a while now, and after switching providers I got a new SIM card. I’ve now noticed that I can’t change the PIN for it through the settings. Does anyone know more about this? That should normally be possible, right?
It is in a weird place.
Settings, privacy and security, more privacy and security, sim locking.
(I have the phone in Spanish so names might be not exactly that, I translated myself).
Many Thanks Ignacio for this answer that helped me to modify my PIN code. 
Muchas gracias ! Merci beaucoup !