Roxanne is one fine tune from the police. Apparently Sting (the singer / bass player / actor / forest saviour) considers the song as more of a tango than reggae. Now you know.
This ActionTab shows you all you need to play through the song. Repeat the segements as necessary.
You can play the chord stabs as all downstrokes (as shown here) or upstrokes instead if you prefer. Whatever chord strokes you prefer, the trickiest part to playing this song is keeping the chord changes clean. Make sure to mute the strings after each chord strike. Getting smooth chord changes can be awkward at first, so slow your strumming tempo down to get your finger positioning practiced first. Build up speed last.
Watch out for the Barred G7th (sus 4) chord. This is struck very fast and ends the reggae / tango sequence. It's the only time where all 6 strings are played. If you have great difficulty playing this chord, just move the previous chord up by 2 frets and play that instead along the top 4 strings. In other words, play the half chord. We won't tell on you.
The last part is fun and gets you rocking out - just palm mute the powerchords and use the occasional open chord strike (as shown in the ActionTab). Have fun :)