There are several variations of Sundial with the bottom leg in varying positions. I’ll describe the straight leg variation, though feel free to play around and see what works best for you.
Start in Dandasana. Bend the left leg and bring it in toward the chest. Thread the left arm underneath to take the outer left ankle/ shin with the left hand and take the left foot in the right hand. Pressing the knee back to open up the left hip, work the left shoulder as far underneath as you can, squeezing in with the left thigh to keep the leg high up on the shoulder or upper arm (whatever is accessible for you). I generally like to take a few breaths to open up the hip, moving the knee around a bit before bringing the shoulder underneath, though that is completely up to you. Once you have worked the shoulder underneath, place the left hand on the floor and sit up as straight as you can.
Take the outside of the left foot in the right hand and with an inhale begin to straighten the leg. You do not need to get it all the way straight here. It doesn’t matter. As you lightly pull the left leg in toward the torso, swivel the upper body open to the right and look up underneath the right armpit. Keep the right leg extended, pressing through the heel and keeping the thigh active. Your left sit bone will probably lift off the floor a little bit, which is fine, but see if you can bring a little bit of that weight back to keep the pose stable.
Keep the breath even and steady and stay for as long as you feel comfortable, then repeat on the second side.
If you have any questions, please leave a comment below. I’d love to hear from you or see you at one of my classes!