This is a great song for beginners. The chords are easy to learn, and there aren't many sections to the song. Plus, there is only 1 strum per bar for most of the song. Bear in mind that this is a reggae / ska style song, meaning that sometimes he will strike chords with upstrokes on the 'offbeat'. It's not hard, just listen / watch the ActionTab and you'll get it.
In the original recording he uses 3 guitar layers, most of which we've condensed into 1 ActionTab here (to show you all the relevant song parts). You will have to pick and choose which parts you wish to use for your own renditions of the song. Unfortunately it is impossible to play them all at once. However, you can easily switch between them as we have done here.
Intro / Break Riff - This is really simple - Just hold and strum the D7 sus4 chord and hold it. Strum it every 8th beat. This guitar runs throughout most of the song, and only plays this one chord (except during the choruses). Notice that there is an 'echo' and long tail to the chord. This is done by using pedal FX - delay and plenty of reverb. You don't need to have those effects to learn the song and play along with it.
Verse Riff - Another really easy riff. Just cycle the same chord shape between 3 positions, as shown. This riff is played on a second guitar (with no FX), while the previous guitar carries on strumming that D7 sus4 chord underneath. Here are the 3 chords he cycles between:
F major - Bb major - C major (repeat)
For the reggae-like strums you must do a brisk upstroke on the offbeat (along with the bass drum), and mute the chord instantly afterwards. Watch it here, and practice it. It's a really cool guitar technique to know, and can be a lot of fun to use in your own songs.
Chorus Riff - For the choruses both guitars play the same 4-chord sequence. The difference is that the first guitar strums each chord once, the other guitar strums each chord twice. Here is the first guitar:
Bb major - F major - C major - G minor (repeat)
Here is the second guitar:
Bb major - F major - C major - G minor (repeat)
We've turned down the 1st guitar here so you can hear this one better. Use the reggae-style strumming again for this.
That is all you really need to play the whole song...but there is one final guitar part to look at for Police enthusiasts: The Lead Fill. You can hear it running through the choruses. It is a palm muted riff played on a 3rd guitar, and we show it in this ActionTab.