Really simple, just follow along with the song and it should sound awesome.
For the verse and chorus use bar chords and play with a reggae up-stroke.
The rest, just make it your own.

basic riff (intro)
e|---------------------------------------------------------|
b|-----------------------6---------------------------------|
g|-2s3h5---2s3h5---3s5h7---7-------------------------------|
d|---------------------------------------------------------|
a|---------------------------------------------------------|
E|---------------------------------------------------------|

verse
F & Gm

Chorus
A#, Am, Gm, F