Gymnastics of Hermes, execution

[Самоучка]

Several times on the forum came across recommendation to do the gymnastics of Hermes. He was doing HS for a long time, I like it. After one event I decided to check whether I'm doing it. I started digging online and found something.

Caught in the web description http://www.ankxara.com/ankhara/gimnastika_N2/ and http://www.ankxara.com/ankhara/gimnastika_N1/.

Share who makes the GG, as it is performed? After all, in these exercises it is important how you breathe, where directed attention and other things (which by the way is not trivial). And desirable thoughts about these two links:

Thank you!