Its not too bad Pete. Just make sure you leave yourself PLENTY of extra wire.. one of my wires is like a half inch short of being too short, like I have to disconnect the oe plug to even be able to see the back of my ohc..
But yeah do what Marty said for the wiring..
On oe pigtail label one wire(e.g. power wire) then connect about 8 feet piece of wire and label the end power, then repeat for the rest of the wires(excluding the ground unless your ground wires uber short and you need some extra length). Then once you have all of them labeled bundle the groups that go together.. like the 3 that go behind your hu, the two to your dome, and the two to the temp sensor It will make connecting the appropriate wires much easier..