Making the ECU fully programmable was done by using a device called Nistune with their Type 3 board. I bought mine via Pete at plmsdevelopments as i was looking for more than just one board. The board is supplied with the connections required and a base map installed (copy of the OEM map on ECU)
Nistune Type 3 Board
The fitting of the board was straight forward just open it solder up solder connector in and then plug the board in.
Then remove a component from the main ecu board.