They sell some stuff at pet supply stores, I think it is called Skunk Off and it works pretty good, the only problem is that you have to wash the cat, so get some nail clippers for cats while you are there. :)
White vinegar, baking powder and peroxide mix shampoo. Yes you will have to bathe the cat Do not get it in his eyes and make sure you sry the ears as best as you can or your kitty may get an infection.
NOTHING works better than skunk off. I work in a veterinary office and that is what we recommend. Simply wet the cat down, and massage it into their fur. Leave it on, don't rinse it off and let the cat air dry. Most veterinary offices will do it for you for the price of a bath.