Arduino mega 2560 + ENC28J60 Ethernet Shield + Sd Card Shield

Hi.
Thanks for your ansewer and help.
I'm a begginer and i don't know many thing about electronics.
So i understand if i have many items who works on spi i must use one pin for one item ?
For my case i must use pin 53 for ethernet and pin 4 for sd card? So i must modify the library for sd or something else?
Thanks again to all.