Sit on the floor with your legs straight out in front of you and touch your toes...Hold the position. If you can't touch your toes, go as far as you can and hold it, each day try and get a little farther. If you can, try and touch your forehead to your knees...
Bring one foot into your crotch, and have the other foot straight out in front of you. Try and touch your toes, hold the position. If you can't reach your toes, do as above. If you can, try and touch your forehead to your knees. Switch legs.
Do the classic soccer/track stretches, they really help.
Lay on your stomach, put your hands so that they're in line with your shoulders. Now push up with your arms, so that you bend backwards...your pelvis should remain on the ground. Stretch your neck out too.
bend backwards and grab your thighs from behind, this will make it so you are able to bend your spine more which is part of the problem. Remember, stop when it gets painful, you can injure yourself.
Lean forward, and try and touch your toes, hold the position. If you can't go down as far as you can and hold it. If you can, try and touch your forehead to your knees.
Doesn't matter when you do it)Lay on your stomach. Pull your foot over your back so your heal basically reaches your hip. Then reach back and grab your knee. Twist your body back in the direction of the knee you are grabing. Repeat with the other leg.
(to be done after stretched out a bit)Sit down with your legs straight out in front of you. Wrap your arms under your legs forward of your knees and grab the elbow of the opposite arm.Pull yourself down until your forehead touches your knees and hold it. This will stretch your spine into the "C" position, and will make it easier to do walk the wall.
(Crack your neck first)Pull your head forward, using your hands to slowly(not forcefully) push your head forward/down. Go until it gets uncomfortable and hold it. Do this every night. After a while, your neck will no longer hurt in the "c" position.
(To crack your back sone)Sitting down with your right leg straight out in front of you, cross your left leg over it(it should be bent with your knee about nipple height or so). Push your right arm against your left knee and twist to the left, hold. Repeat with the mirror version.
(To loosen the ligaments around your groin) Bring your feet in as close as you can to your groin and bring them together so the bottoms touch. Now, gently, push down on your knees. They should almost bounce, repeat several times.
I hope these helped, if you have any questions about a particular stretch, send me a PM and I'll try and clarify.