The Inverted mandala is a more challenging version of the Sarvangasana (shoulder stand) mandala from Day 73.
It includes viparita dandasana from Day 82 but because it doesn't involve the drop back into the posture sit can be practiced as a stand-alone subroutine.
Viparita Dandasana is quite is an intense backbend so some backbend preparation is advised as warm up, the back bend vinyasas from the tadasana subroutine, Day 1, is a suggestion as are some of the pelvic lifts from Supine as well as perhaps urdhava danurasana.
More intense than the backbend is the belly twist as you flip first one way and then the other as you walk around. Twist preparation might include Parsva-bhangis, from Day 2 and especially the belly twists from Supine, Jataraparivritti Subroutine day 64.
As you lower your feet to the mat, ground your head and elbows and walk around, clockwise, on the inhalation. When you can no longer keep your feet on the floor come up on to your toes.
Exhale, take one last large step with your left foot, hold the exhalation, bring your right hip up, take the right leg over the left, twist at the waist and flip your leg all the way over so your right toes lands on the mat in front of your left foot.
The higher your able to keep your hip the more you'll be able to keep the head and elbows anchored on the mat.
Continue walking around, pause for a breath at viparita dandansana then carry on around clockwise as far as your able.
Again on the exhalation, take one last step with the right foot up on the toes, the hips high. Hold the exhalation bring the left hip over twisting at the waist as much as possible, step over with the left foot and give a last flip of the hips to bring your left foot all the way over the right landing on the toes.
Continue on round to the starting position and return to Sirsasana