Possibly snatch high pulls would help you.
But, you also have to consider that once you fully extend your hips with shoulders slightly behind the bar, the time for you trying to move the bar upward is over. From that moment on, you need to be getting yourself under as fast as you can. The shrug and elbows up pull should be happening as your feet are moving out to squat stance, so that way it is violently forcing you underneath the bar.
To improve the second pull, though, try to keep your weight on your heels, be using your lats to push that bar back into your hip crease as hard as you can, stay over the bar as long as possible, and violently explode your hips as hard as you can. One cue that really made the hip extension make sense to me was McCauley's "uppercut the bar with your hips." If you think of an uppercut punch, yes your fist is moving forward slightly, but the power is all being generated UP.
Hopefully that helps a little!