But in this site: http://arduino.cc/en/Main/ArduinoBoardMega
It's said tht the spi pins used on the ethernet shield are broken out on the ICSP header
So the ICSP header does the job for me and I don't need to do any hacking, right?
I made the pin changing though, but it didn't work out.
I have the official Arduino Ethernet shield, and an arduino mega1280 board