As your opponent starts to set up the over under pass create a frame the open your leg to create space to grab behind your opponents armpit. Extend your outside leg and then pinch your knees to control the arm. Use the arm that was framing on your opponents arm to grab your opponents belt with a palm up grip then use your outside leg as a pendulum to help you sit up and grab your opponents leg. Step your leg on the floor and come up to the top and step your leg over your opponents legs so both of their legs are between yours. Grab around your opponents head and pull them to you and use your other hand to control the bottom leg. Finish the pass by circling your leg and walking to the hips until your bottom leg touches their hip, then block the hip and switch your hips to establish side control.