Here we have Marcelo Garcia demonstrating one of the ways that he uses to pass the Seated or B-Fly Guard. He uses a elbow & collar tie as he stands up with one leg splitting his opponent's guard. By doing this he can control his opponent's movement better as he sets up his pass. These are solid principles for passing this type of guard in No-Gi Grappling.
On top of that he demonstrates how he attacks the Seated Guard with his patented Guillotine. This is a nice option that flows right from the elbow & collar tie. Just be sure not to take a dive head first into the ground ;)