Use RFID-RC522 with other Pins I'm wondering where the pin setting is manifested in the library.
I want to use the RC522 with other digital pins than the default 50-53 pins, because I am using a shield for a display on theese ports. 

Where can I change the used ports?
why are two ports user-defineable #define RFID_SS  10 #define RFID_RST 5 while the rest is not?

I am with this Playground-Guide using this library from Github on my Arduino Mega
SPI 
The RFID_SS pin is the slave select pin.
So you can have another arduino pin for a LCD_SS select.
Having RfID_SS =low - talk to RFID.
Having LCD_SS =low talk to LCD via MISO.
Note: Drive other slave select High otherwise they'll both get the data.
Having only one device in communication at a time.
Cheers
Nik V