iron. Cut the old connector wires as close as you can to the connector to give yourself maximum slack. Like Synd said, the hardest part is leaning over the engine the entire time (hard on the lower back), so try jacking the car up a bit to ease the pain on the back. Shrink tube is a must.
If you have the old style injectors, I would suggest doing the "12volt switched power" mod found here in the FAQ: 12v switched inj mod
I did the switched power mod when I did my injectors and it literally took me ten minutes; the hardest part was de-pinning one of the stubborn pins.