From the De La Riva guard stretch your opponent out by pulling their arms and extending them with your legs. As they posture up use the momentum to sit up, release the grip on the near arm and swim that hand under the leg feeding the far arm to your free hand.
When your opponent pushes your leg between theirs turn your hips inside as you grab the far leg and insert your hook. When your opponent blocks the previous sweep by posting his hand on the mat pull your opponent towards you and push his leg down as you roll back to the top.
To take advantage of the situation and pass your opponents guard release the arm grip and place your hand to the mat then walk towards the head trapping his leg between yours. Next grab around his head pulling them tight to you so you can apply good shoulder pressure. Switch your hips, circle leg free, then pull his sleeve up as you walk to the hips. Once your bottom knee touches the hips complete the pass by releasing the sleeve and using the arm to block the hips as you switch your hips square with your opponent.