I have never done a swap before, but wiring looks like a really daunting task to me,when I look at pictures of wiring harness's,etc. Looks like a big octopus of wires.

How bad exactly is it? I look at wiring diagrams on the internet and the only thing that runs through my head is "omg wtf".

 

I do pretty good at it. With a decent diagram and an understanding of how electricity and digital signals are sent it is pretty straightforward.