The lead guitar only plays 2 simple fills through the choruses and outro (it is silent through the verses). It's simple stuff and very good practice for beginners. We're showing the last half of the song, because the same riff is repeated throughout (so there's no need to show the whole thing).
Chorus Fill - The chorus fill is just a D major shape chord, held at fret 9 (which gives us a B major chord). Keep your first finger on at fret 9 of the high E string as shown, and remove your 3rd finger. This alters the chord to B sus2. Keep repeating these 2 chords over and over through the choruses.
Make sure your thumb is in the centre of the back of the fretboard so that your fingers drop down onto the strings from a high angle. This will ensure good clean notes with no fretbuzz or accidental muting.
The lead guitar is silent during the verses. It only plays during the choruses and outro.
The last chorus is played just like all the others, but remember that at the end of the song everything is shifted up by 2 frets for the Outro. The picking pattern and chord shapes are exactly the same, just higher by 2 frets. This means the chords are now C# major and C# sus2.
Concentrate on getting the timing right. Each note should last the same duration of time.