If you listen to any Ozzy or BLS, you have heard AH. Just make sure you are using some nice deep distortion, Bridge pickup (postition 3) if you have humbuckers, Bridge/Middle (position 4) if your on single coil. It is easier to do on humbuckers, but it is possible with single; I do it everyday. Then, just find all of the sweet spots, like where to pick, how hard to pick, how hard to hold the pick, and how much of your thumb needs to hit the string. Happy squeals!