Watch the Bring It! online guitar lesson by TrueFire from Rock Guitar Greatest Hits Vol. 1
Lesson Source: Shane Theriot's Rhythm Mojo
The trick to getting this riff together is to get the main repetitive riff to lock with the track. Once you get this together, you add the low E string. Keep the right hand (or your strumming hand) kind of loose. The trickiest part to this idea is the open string riff. Make sure you get the hammer-ons and pull-offs in the right place. This will make this idea much easier to play. Also, work on this and all these ideas with a metronome! The wah is optional here, feel free to add your own effects or none at all to it.