The Ustrasana is the scary pose for me here. In Ashtanga we dropback into kapo but here you drop back to Ustrasana, ideally straight on to the heels and then push up straightening the arms as much as possible, very deep backbend. Then you lower down into your kapo. I'm looking at Sweeney's Kapo B in his book, he takes the heel in Kapo A then releases them before pushing up to Kapo B.
Oh and of course in Vinyasa krama the heels as well as the knees are supposed to be together for the kapo's etc dropbacks too for that matter, maybe one day.
Eka pada raja Kapotasana is of course scary too, balance is the concern here and figuring out where the heck your foot has disappeared to.
So here's the full sequence with some clumsy editing (sorry, hadn't planned on filming it just then) and below the links to the individual subroutines on the sister blog Vinyasa Krama yoga Sequences and subroutines
Now you don't have to practice this as a stand alone sequence, although it's useful at first to see how the postures relate to and often build upon each other. You can practice the subroutines found within the full sequence separately. I tend to do the kapotasana subroutine after most of the Vinyasa Bow sequence every other day to give a strong backbend focus. If your still working on developing your lotus then the Vajrasana subroutine might be a nice option towards the end of your practice. Here's a link to some of my daily practice sequences to give one idea of how you might develop a practice out of Vinyasa Krama subroutines.
And here are the links to videos of the individual subroutines