Of course rebirthing is best done with a qualified rebirther in order to experiment the full benefits, at least at the beginning. But doing it or learning it alone, can be also very beneficial for body and mind.
About this wonderful rebirthing technique rediscovered by Leonard Orr :
https://en.wikipedia.org/wiki/Breath..._and_sub-types
The full breathing guided session
https://www.youtube.com/watch?v=3zRe1xdvKhA