I've heard that porcupines are the safest animal to eat raw too. I shot a decently-sized porcupine last fall during deer archery season, and ate the liver and heart right from the carcass while field dressing it. I found them to be quite tasty. The muscle meat was okay, it was fairly lean so bland in taste but certainly not as bad as chicken.
Although it's theoretically possible to 'walk right up to one and club it in the head', I advise against that idea. Although they walk slowly, they're very quick to whip their tails around and plant a couple dozen quills into your calf or thigh, and the quills are barbed and a terror to get out. I accidentally got a few in my thigh while carrying the dead porc out of the woods. Nasty!
If you have in mind to kill one, I suggest a simple bow made with a long, thin arrow with a sharpened tip. Neither the bow nor the arrow need be fancy, just sturdy enough to pierce both of the porcupine's lungs so it dies quickly, within a minute or two. That way it doesn't suffer too much, and you don't have to risk getting quills in you when it thrashes about. Or at least the risk is much less.
Alternatively you could make a spear from a sapling, although realize that the closer you get the less predictable the porcupine will become and the quicker and more volatile its movements will be, so be careful. I've heard of folks trying to kill porcupines with spears during survival trips and ending up in the emergency room when quill injuries got infected.
