Watch the Alternate Picking Lick online guitar lesson by TrueFire from Play Rock Guitar 1: Quick-Start for Beginners
This is a great rock riff to work on your alternate picking. This riff from Ozzy Osbourne's "Crazy Train" has some nice jumping back and forth between strings and a cool pedal point lick. In order to get this lick up to full speed you really need to work on being efficient with your picking and start slow and gradually work it up. Keeping your fretboard hand fingers low and close to the strings at all times will also help you play it much faster. Just think minimum movement with both hands and you will be fine. Then it is just a matter of repetition to get it up to speed.