Don't even worry if your school doesn't offer the class for it. A friend of mine and I did self-study for one AP test, and started about 3-4 weeks before the text. I didn't "ace" it, but I got a high enough score that it got me out of required classes in college.
True, also the definition of "aceing" should be adjusted for the AP exams. I took the Physics C Electricity & Magnetism exam without taking the class, you only need to get something like 65% of it right to get the highest score (which some shockingly small percentage of people even do). That isn't hard at all if you put your mind to it. When I got to college it knocked off a 4 credit class with a 3 hour lab each week. 2 weeks of studying saved me hundreds of hours of work in college.