(Please NOTE there are multiple ways to get into this stunt, and we'll explain it from the ground with a spot for assistance).
Start with a flier, a base, and a spotter. Have the base stand there with his right hand up and elbow down near his waist. The flier will stand their in front and to the base's left, and overlap her hands on top of the base's right hand. Now have the spotter stand in the front and grab the flier's left foot. The base will place his left hand on the flier's stomach (on her right side).
On count the flier will dip/jump, keep her arms locked, and ride her hips up to a handstand. The spotter will toss/guide the flier's left foot up for assistance, then move to the back to spot. The base will dip with the flier, follow her hips up with his left hand, then begin to lift the flier with his right hand as soon as the flier has gotten her hips up higher than his hand. Make sure the base fully extends his right hand, and the flier points her toes for the finish.