How do i connect to the ECU of my 1.9TDI VW Golf Mk4 to remap/reflash it.. i have bought cable and software?

i have bought the cables and software to do it and when i tryed to connect through the 10 pin connection in the car it wasnt picking the ecu, i was told i had to take the ecu out and do it that way so i have the ECU here open and im puzzled.... any help?