strum pattern for chorus and bridge is 
D D  U     D (the pattern is very unuaslly timed so you should listen to the recording to get it)
/ - single strum


intro and first verse:

|----5-3---5-3---3-
|--3-----3-----3---
|------------------   play 20 times for
|------------------   intro and first verse
|------------------
|------------------


chorus:

first chorus play 2 times:

C    D    Em    G


second verse:

|----5-3---5-3---3-
|--3-----3-----3---
|------------------   play 15 times for
|------------------   second verse
|------------------
|------------------


play chorus 4 times through except on forth time play:

C    D    Em    A    D
                /    /


bridge:

A    C    D    D       play bridge 4 times
     /    /    /


third verse:

|----5-3---5-3---3-
|--3-----3-----3---
|------------------   play 15 times for
|------------------   third verse
|------------------
|------------------


play chorus 6 times


fourth verse:

|----5-3---5-3---3-
|--3-----3-----3---
|------------------   play 10 times for
|------------------   fourth verse
|------------------
|------------------