G|---------------------|
D|---------------------|
A|---------------------|
E|-3-3-3-3-3-3-/8-/13\-| INTRO/VERSE/CHORUS.

You need to play the sliding down to the 8th and 13th fret one after the other really fast to keep in time.
Just listen to the song.

G|-------------|    |----|
D|-------------|    |----|
A|-------------|    |----|
E|-3-3-3-3-3-3-| 4x |-/8-| I'm sure that he slides down to the 8th right at the end as it fades out. Believe me!

And that's that...