Watch the Longest Night - Rhythm online guitar lesson by Jeff Scheetz from Rock Solid
This is a fast shuffle and your right hand will be wearing out on you! So keep it relaxed. Don't tense up or you will cramp up. The intro lick can be changed and varied a lot, but remember, this is the rhythm not the solo.
A thing to bear in mind is that just because you CAN change it all up doesn't necessarily mean you SHOULD! Work with this rhythm using a metronome and that will give you the confidence to kick it up a notch or two live.