astra diesel fuel pump?

Hi, i have a 2000, 20 cd dti astra that has stopped running.It was ok when i parked it up one night and would not start the next morning,will turn over brilliantly but just wont fire up. I have good mechanical knowledge and ave been told it injector pump.it fly by wire set up so would like to know if replacing it would be easy or would i need to have it re-programmed, would i need the ecu off donor car.Any help would be very grateful . Thanks