This a short video showing (most) of the Vinyasa Karma postures leading up to the leg behind head postures in the Asymmetric sequence. Obviously I'm whizzing through them here, just trying to show how they build on each other and gradually work on opening up the hips. Normally you'd be staying in these postures for three to five long, slow, inhalations and exhalations.
Then I try and explain, poorly I'm afraid, how I personally approach getting my leg behind my head, before carrying on through some of the more advanced LBH vinyasas that come up in other Vinyasa Krama sequences.
The full asymmetric sequences can be found HERE as a practice sheet.