The lead guitar is quite straightforward in this song. It is there mostly as a fill / accompaniment rather than a standalone solo effort.

Guitar swells are used in this lead. Swells are where you adjust the volume knob on your guitar whilst playing. Typically, turning the volume down, striking a chord or note, then turning the volume up slowly. This creates a 'swell' - starting quietly and getting louder, often turning the volume down again and doing it all over again. Many guitarists love using this technique with vibrato. This is no exception.

You can hear the swells here. Just be aware when doing your own swells not to turn your volume completely off. Just go low at about 3 (out of 10), pick the strings, and use your (little) finger on your picking hand to adjust the volume up to 10. It's usually best to use your little finger for adjusting the volume knob because it is closest and also it means you can keep your pick (held between thumb / forefinger) closer to the strings. This is useful during more intricate solos.

Notice that for many of the swells, the B string is omitted. Just lightly touch that string with your first finger as it frets notes on the adjacent G string. Pick all 3 strings, and the middle string will be muted out by the adjacent strings. They will be louder because they are fretted, and will drown out the middle B string if you have muted it correctly. If confused, go here to learn more about the muting technique.