Even though there is no bass, this is what you could play:

|----------------------------------|
|----------------------------------|
|-----------------5-5-5-5----------|
|-7-7-7-7-5-5-5-5---------0-0-0-0--|

|----------------------------------|
|----------------------------------|
|-----------------5-5-5-5----------|
|-2-2-2-2-5-5-5-5---------0-0-0-0--|

|-------------------|
|-------------------|
|-------------------|
|-2-2-2-2-5-5-5-5-2-|

This are the riffs. Play the first a couple of times, then the second (one or two times)
and then the third once. It's easy to figure out how many times you have to play the first riff.

Enjoy!!!