In kneeling place one knee on a book.
Stabilize your pelvis of the book side with your glutes.
Lift your other hip with the book-side glutes until your pelvis became horizontal.

1. Raise your non-book side knee. Before you start raising lift your heel up (flex your knee) to make space for your foot.
Keep the max flex in your knee and squeeze.
2. Move your knee back. Put it on the floor slowly and softly.

Try to drive your leg in a straight line