Stand with your right leg facing the wall. Make sure when you bend your front knee there is room to wedge your block between wall and knee, then come back to the position where your feet are wide, left foot turned in, slightly, and right foot facing the wall. Now, establish the back leg. Press the foot into the floor, particularly aware of the outer edge. Turn the inner left thigh out, keeping the left hip moving away from the wall. (It's important to note that the pelvis is not completely square, if it were our knee would be very strained).
Keep those actions and bend the knee toward the wall, placing the block between wall and top shin. Lengthen your inner thigh toward the block to keep the block from falling on your toes! Did you lose the action of the back leg? Find it again. Now that your thighs open away from each other make sure you lift the pelvic rims (hip bones) up toward the waist and lengthen the trunk.
Take your hands onto your hips and explore the leg action. What does keeping the block there do for your inner thigh? Can you stay connected to the back leg? What does the pelvis feel like to you? Your back?
Make sure you retrieve the block before straightening your front leg. Then, turn your feet and change sides.
Try the pose again without the block. Notice the difference in the ways of working.
Enjoy exploring your inner warrior and let me know how it works for you!