Standard EADG tuning
The main section, Part 1, is played repeatedly, followed by alternating between Part 2 and 3. There is only one area of the song where Part 4 is used. I think he changes it up a bit throughout the song by adding slides, holding notes longer or leaving some out.
Part 1.
G |———————————9/11——————
D |——————7—9———————99———
A |—7—9—————————————————
E |—————————————————————

Part 2.
G |————————————————————
D |————————————————————
A |————————————————————
E |—0—77—55—33—22——————

Part 3.    
G |————————————————————
D |———————————4—7—4————
A |———————5—7——————————
E |—0—5—7——————————————

Part 4.
G |—12/14—12—11—7—9————
D |————————————————————
A |————————————————————
E |————————————————————