Chord Chart Available in Songbook
The lead guitar part is using a pattern of 6ths played with a finger and pick, called hybrid picking. Once you get comfortable picking pattern just move it up the neck to the E and D chords in the same barre chord shape. Also make sure to play your notes super short to get that staccato phrasing.
The guitar chords Bob Marley uses for this song and the classic I, IV, V chord progression in A major. These chords can be played in the open position for acoustic guitar, or you can play the barre chords I have outlined in the chord chart. The rhythm guitar part is played using a downstroke on the offbeat and is explained in detail in my lesson How to play Reggae Rhythm Guitar.