C:    Em:   G:
E|--0--|--0--|--1--|
B|--1--|--0--|--0--|
G|--0--|--0--|--0--|
D|--2--|--2--|--0--|
A|--3--|--2--|--2--|
E|--0--|--0--|--3--|

 before the G is played (if you listen to the song) there are two notes played before the G so I'll write some made up tabs so you get the picture..this is hard to explain in words so I hope you understand

LISTEN TO THE SONG TO KNOW HOW MANY TIMES TO PA Y EACH CHORD

C---Em---then the new tabs are each played only once
x= don't play those strings
  
E|--x--|--x--|
B|--x--|--x--|
G|--0--|--0--| -> Then just move the low e finger to fret 3
D|--0--|--0--| ( which makes you play the G )
A|--2--|--2--|
E|--0--|--2--|