The basic chords in the song are F, D minor, and B flat. When I play the chords as a solo piano piece, I like to think of the band that would be playing and try to equate that sound to solo piano. It's a balancing act between trying to sound like a full band, and trying not to sound to full, or overplayed. I like to add tenths to my left hand, but not everyone's fingers stretch that far.
In the middle of the song, he does a little instrumental. It goes from B flat to D minor, back to D flat, then repeats. After that little break it goes back into the chorus.
Now let me talk a little bit more about my left hand technique when playing the song. When the song started, I was just playing single notes at eighth note intervals. This is good, because the song starts off sort of delicate. Later in the song though, the full band joins in. To create this full sound I like to add a fifth to my left hand. This gives the solo piano piece a bit more of a full sound. As the song progresses, I switch to tenths as mentioned above. The switch to tenths gives the song an even fuller sound.
So those are the basic chords and basic chord patterns. In the recording he changes it up a bit. As you progress in your playing, you can try to make your own changes and increase the complexity of your improvisation. Good luck, and have fun with it.