Very easy. Listen to the song for the strumming pattern, but it's basically two
down strokes on the C and then down/up/down on the other chords. 

CEm F (133211@1)               G (320003@1)     CEm
Play something that we need to hear
F (133211@1)              G (320003@1)      CEm
Play to make the ghosts appear
F (133211@1)        G (320003@1)         CEm FG
Play until the bottles gone

That chord sequence is then repeated through the song, until:

Em (022000@1)           AmPlay (x02210@1)it in the streets, Play it in the schools
F (133211@1)             F (133211@1)                    G (320003@1)            G (320003@1)         CEm FG 
Play it for the ones out there who've never seen what playing can do

Then it returns to the main chord sequence until the end of the song.

Pretty simple, but a great song.