Summarize this article:

The bridge, also known as the press, is an advanced back stretch, but also a key component of the valdez. Start by laying on your back with your legs bent at a 90-degree angle. Keep your feet planted on the ground.  Place your hands by your ears, palm down. Make sure your fingers are pointing towards your feet, and your elbows are pointing towards the ceiling.  Lift your back off the ground by pushing up with your hands and feet. Keep your hands and feet on the ground as you lift. Your goal is to lift your back completely off the ground while keeping your arms and legs straight. Standing straight up, lift your arms over your head. Keep your arms straight, with your palms facing the ceiling, and your fingers pointing behind you.  Arch your back backward and slowly move your arms closer to the floor. Look for the ground behind you.  Use your arms to feel for the ground so that you don't hit your head when you land. When you feel the ground, firmly plant your hands to complete the backbend.  If you are having trouble performing a standing backbend, use a wall to help you. Stand facing away from the wall. As you start your backbend place your hands on the wall and walk yourself down to the ground. To do a backbend kick-over, start by doing a standing backbend. Once you've completed your standing backbend, kick your legs over your head until you land back on your feet.  Make sure you have enough momentum to get your legs over your body, and onto the ground behind you. If you are having trouble kicking your legs over, try performing a bridge in front of a wall. Keep your feet next to the wall, and walk your feet up the wall before you push off.  You may find that you can't quite kick your legs over your body the first few times that you attempt a kick-over. If you try to kick, but keep landing in the bridge position, that's okay. Kick-overs are difficult, and it will take a lot of practice to complete one. A back walkover is a combination of a backbend and kick-over. Standing straight, extend one leg directly in front of you. Keep your other leg planted firmly on the ground.  Keep your arms close to your ears with your hands in the air. Keep your arms straight and tight.  Move into a standing backbend and let your extended leg move with your body. Keep your leg straight and don't let it move from side to side.  As your hands touch the floor, let your extended leg go over your body. Your standing leg should follow until both feet are on the ground. Finish in a lunge position with your front foot pointing forward, and your back foot slightly turned out.

Summary:
Perfect your bridges. Practice standing backbends. Learn to do backbend kick-overs. Teach yourself back walkovers.