(C)   (G5)   (Am)
E|-----0-| --3--  --0--
B|-----1-| --3--  --1--
G|-----0-| --0--  --2--
D|-----2-| --0--  --2--
A|-----3-| --2--  --0--
E|-----x-| --3--  --0--

this is the riff played over and over and over throughout the whole song.

E|----0-----3-3--0----------------| |
B|----1-----3-3--1----------------*|
G|----0-----0-0--2----------------| |
D|----2-----0-0--2--3-3-2-0h2p0---| |
A|-3--3-----2-2--0--------------3-*|
E|----x--3--3-3--0----------------| |

this is a really easy song and it took me about five minutes to figure it out after 
i downloaded it. this also sounds good with the marley version or over an Am pentatonic
scale:

E|--------------------5-8| 8-5---------------|
B|-----------------5-8---| ---8-5------------|
G|-------------5-7-------| ------7-5---------|
D|---------5-7-----------| ---------7-5------|
A|-----5-7---------------| ------------7-5---|
E|-5-8-------------------| ---------------8-5|

Or a Cmaj sliding scale

E|----------------------------------15-17-20|
B|--------------------------13-15-17--------|
G|---------------------12-14----------------|
D|-------------10-12/14---------------------|
A|--------10-12-----------------------------|
E|-8-10/12----------------------------------|

and back down

E|-20-17-----------------------------|
B|------20-17------------------------|
G|-----------19-17-------------------|
D|----------------19-17--------------|
A|---------------------19-17---------|
E|--------------------------20-17/8-5|