I think he uses barre chords throughout the song until the change of key (apart 
from the Am), then I think he uses both.
But just do however it sounds better to you. Enjoy!

Intro: C C G G

C (x32010@1)                               
If I were made of stone could you shake my soul
       G (320003@1)                   
To its very core like no one could before
        F (133211@1)                   G (320003@1)                        Am (x02210@1)FNow (133211@1)you turned me into such a fool and you know it's true
         F (133211@1)                   G (320003@1)                         C (x32010@1)CAnd (x32010@1)if I never make it back to you, just know I wanted to

C (x32010@1)                     
If I were made of stone could you shake my soul
       G (320003@1)               
To its very core no one could before
          C (x32010@1)              
It was easy to block the thought of you
       G (320003@1)                         
But you get right through and I'm glad you do
        F (133211@1)                   G (320003@1)                        Am (x02210@1)FNow (133211@1)you turned me into such a fool and you know it's true
         F (133211@1)                   G (320003@1)                        C (x32010@1)CAnd (x32010@1)if I never make it back to you just know I wanted to

F (133211@1)                    BbI (x1333x@1)don't know how I can tell you straight
F (133211@1)                    Bb (x1333x@1)      GIts (320003@1)gotta be just the right time anyways
F (133211@1)         G (320003@1)                                 BbI (x1333x@1)swear to god one day I'm gonna say it to your face
BbYeah, (x1333x@1)one day

Solo: F  Bb
      F (133211@1)Bb (x1333x@1)name="chord_320003@1">G
      F (133211@1)G (320003@1)name="chord_320003@1">G Bb (x1333x@1)name="chord_x1333x@1">Bb

DIf (xx0232@1)I were made of stone could you shake my soul
       ATo (x02220@1)its very core like no one could before
        G (320003@1)                   A (x02220@1)        Bm (x24432@1)                        ENow (022100@1)you turned me into such a fool and I don't know if you know it's true
         G (320003@1)                      ABut (x02220@1)if I never make it back to you just know I wanted to

D (xx0232@1)                     A (x02220@1)                     G (320003@1)A (x02220@1)  Just know I wanted to, just know I wanted to
      Bm (x24432@1)                        EAnd (022100@1)I don't know if you know it's true
         G (320003@1)                      A (x02220@1)                    DBut (xx0232@1)if I never make it back to you just know I wanted to