Drop D Tuning
D A d g a e

Technically your picking this D chord for the intro and whenever else he does it:
e------0--------------|
a------0--------------|
g------6--------------|
d------7--------------|
A------5--------------|
E------0--------------|

Heres some what of an easier version but i think just listening to the song
and just picking kinda like he does it much more easier.  It's quiet an easy
song.  

**Let all the strings ring when u pick and strum chords unless stated otherwise**

Intro 
e--------0-------0------------0-------0--------------------------|
a-----------------0--------------------0-------------------------|
g-----6------------6--------6-----------6----xxxxxxxxxxxxxxxxxxx-|
d---7----------7----------7---------7--------444444444444/777777-|
A-5----------5----------5---------5----------444444444444/777777-|
E-0-------------------------------0----------444444444444/777777-|

e--------0-------0------------0-------0--------------------------|
a-----------------0--------------------0-------------------------|
g-----6------------6--------6-----------6----xxxxxxxxxxxx4--4-4--|
d---7----------7----------7---------7--------4444444444444--4-4--|
A-5----------5----------5---------5----------4444444444444--4-4--|
E-0-------------------------------0----------4444444444444--4-4--|

Verse, Play part Intro

Chorus
e---------------------------------------------------|
a---------------------------------------------------|
g--99999999999999----xxxxxxxxxxxxxx--99999999999999-|-Than back to
d--99999999999999----44444444444444--99999999999999-| Picking D
A--77777777777777----44444444444444--77777777777777-| Like Intro
E--99999999999999----44444444444444--99999999999999-|

Thats Pretty much all your really need to know.  Just listen to the song.
The Chords just repeat itself.