Dan and Erin Ries are two amazing instructors who are so skilled at teaching and break everything down into such detail that the moves become easy to learn. How they describe things really makes you comprehend the techniques.
Part three of the series focuses on the Chuybar, which is a great submission to hit from half guard. This is a great option to hit if you are having a hard time finishing the Kimura but are good at getting the grip. They really show how to move your hips to use the technique even if they are hiding their hand hard.