The best way is to take the whole loom out and cut all the MFI bits off you dont need. You will be suprised at what is left. While it is out check the whole loom as its very old now and fix any damaged wires and then either tape it up or zip tie. It will look so much better and easy to wire ms. I pulled all my loom out and did it all in the living room infront of the fire lol

If you do take it out you might aswell put a new wire in for the fuel pump. It will eliminate any future problems.