Here is the sequence slowed down a bit. Once you learn the notes, practice playing the riff very slowly. Concentrate on your timing and the transitions from 8th notes to 16th notes and vice versa. Before you start applying speed, make sure you can feel the rhythm and the relationship between the slower notes and the faster notes. The transitions need to be smooth and seamless.
Once you have it down, get ready for the backing track in the next lesson.