It's pretty easy. You can undo the harnesses and run them into the fenders from behind the strut towers and in front of the headlight panel. That'll take care of most of them, and you can do the hood latch release cable in the same manner. Back when I did mine the only things that needed to be lengthened were the AC relay plug, battery cables (to route them the way I wanted), and a couple vacuum hoses. The toughest part was hiding the starter solenoid and all the corresponding wires. I didn't lengthen any so it made for a pain in the ass to fit everything safely and out of the way so I could put the fenderwell back in place. If you want to lengthen those wires you'd probably save yourself some time and a headache.