2 Part Technique - Proper weight distribution is an important factor for successfully passing your opponent's half guard with the Back Step Pass. You must find the balance between control and base, wherein you can hold your opponent down yet not over-commit your pressure to his advantage. Too little pressure, and you run the risk of letting him sweep you with his underhook; too much pressure, and you could get reversed with a simple roll. Once you've established yourself comfortably on top of his chest and shoulder, look to bury your hand into his armpit and dig up an underhook. There isn't a trick for acquiring this necessary component of the pass; It's going to be a fight. Armed with the underhook, you can shift some of your weight onto his head and kick your leg free of his half guard. Make sure to kick at his bottom leg and not the top, otherwise he might capture both of your legs into his guard. After passing, and if he manages to pummel back for his own underhook, lay your weight onto his arm enough so that he can longer improve his position so easily. When the time is right, release your pressure and lift his arm up, effectively spring-loading his arm directly into the Spiral Armbar. Step across his chest and sit off to the opposite side, keeping his arm tucked tightly underneath your armpit. Finish by adjusting your pinching squeeze between your ribs and knee, depending upon the direction of his elbow joint.