To begin, let's keep a close eye on the shapes, but also the 16th-note picking pattern (D-U-U-U). This pattern deviates here and there throughout the etude, but for the most part, once you master this cleanly, you're good.
The first shape descends through a traditional 5-string "D minor shape" sweep arpeggio, while connecting with one note per sequence to the 7th fret Em barre-chord shape. These patterns often trip guitarists up, so be sure to note the fingering being used, as it is quite imperative to nailing these licks up to speed.
Make sure to maintain an even 16-note sound throughout - the goal is to achieve as consistent a "machine gun" effect as possible, rhythmically, regardless of arpeggio shape or picking.