Sit with your back flat against a wall with your legs straight out in front of you. Reach out with your hands as far forward as you can bracing with your finger tips. Push your fingers hard into the ground and pull your legs up towards your chest. You may experience some cramping in your quads or hip flexors, this is normal.
Tight hamstrings will make this movement more difficult, if you are unable to perform the Pike L-Sit with straight legs bending your legs will make the movement slightly easier.