Welcome to... "Micro-Lesson 256"
The riff is best performed using either Hybrid Picking or Finger-picked Technique. In measure one we're working from an "F Power-Chord." The chord is separated with bass to treble tones. The chord is followed up by a short "Pentatonic Lick." The next measure applies a very similar chord and lick idea on the VII-chord of the key, (Eb power-chord).
In measure three, the VI-chord is covered by running through an arpeggio of the chord, (Db power-chord). After that, there are a short series of 6th intervals performed between the 4th and 2nd guitar strings. The 6th intervals run laterally from 8th to 6th to 5th and 3rd frets. This is a great sound that really helps connect the phrasing into our final measure.
In measure four, the progression turns around by playing arpeggio concepts across an "Fm" and a "C7" chord. Both chords use the note of "C" in the bass. Overall, this progression is fairly easy to perform through and since it uses very popular chord movements in it's harmony, it can be transferred to many other musical situations.
Memorize the movements prior to building speed. Use a metronome to really get this riff flowing nicely. Enjoy!
Micro Lesson 256: "F Minor" Pop-Rock Riff