Watch the '61 SGLP: Intro Section online guitar lesson by John Jorgenson from Eclectic Electric: 61 SGLP
The second phrase of the intro is something that's going to be repeated often throughout the song, and has lots of classical rock elements in it. It has groups of three eighth notes in 4/4 time, so it gives a sense of shifting time. You start again on the E string 7th fret (B), and then you hammer from 7th to 9th on the A string, and then play the 9th fret on the D string. Then, you do the same hammer on, but you have a different top note. Move the whole thing down two frets, then move it down a string. You finish by playing a G, and don't forget to add vibrato to it!