In this video I show the next logical move after you have obtained a deep underhook. Having a deep underhook opens up the pathway to the back!
There are plenty of ways to finish coming out on the back, in this video I show one way to do it. I emphasize pulling my opponent back into me instead of hipping up and over. I have heard that by having that hook in you hare "half way to the back" but in reality that hook is as much of a liability as it is a benefit. If you take the back the way that I show in this video you will have a much higher success rate in finishing.
Also I show that you should remove that bottom hook before shucking out the back. This part can be optional and it depends on how long your body is in relation to your opponent. If you have short legs you will find that it is very easy if you take your leg that is hooking the Half Guard out before going, if you have long legs like I do you may feel that you have enough room without taking your leg out (and if you watch reps 2,3,4 I leave my leg).
In the event that your opponent gets some of his/her base back during this period (where you dont have a hook in) be prepared to take your top knee and gently (or violently depending on your environment) kneeing him/her in the butt. This will be covered further in the future but if you want to see what I'm talking about watch the Fedor vs Henderson fight.