So I've bassically been watching a video where McFly perform this song at the Rock 
in Rio and I tought about tabbing the intro as nobody did it yet so here it is! :)

E--------------------------------------------|
A--------------------------------------------|
D--------------------------------------------|
G-------------------------8------------------|     
B----12---10---8------7-8---8s12-------------|
e----10---10---10---0------------------------|

E--------------------------------------------|
A--------------------------------------------|
D--------------------------------------------|
G-------------------------8------------------|     
B----12---10---8------7-8---8----------------|
e----10---10---10---0------------------------|

Chords are always the same: 

Verses:
Em, C, D, C, Em
Em, C, D, C, G

Chorus:
C, D, Em
C, D, G

you may wanna play

E--0-|
A--3-|
D--0-|
G--0-|   
B--3-|
e--3-|  instead of C cause it's sounds cooler ;)


So, that's for the intro, but after you play Em the first time you want to do:

E-----0--2--3-------|
A-------------------|
D-------------------|
G-------------------|   
B-------------------|
e-------------------|

It just sounds better.

Hope this helps you :)