From the Section - 'Working With The Breath'
"One eventual goal of our standing meditation is Whole Body Breathing. Although, once this is achieved, that is, hardwired and happening on it’s own, the sense of breath will seem to go away as our super-refined focus becomes fully absorbed in feeling the Chi, both inside the body and out.
Here is a good method to begin unifying the breath. Start by breathing into the upper back and lower belly (Dan Tien area) simultaneously. As you continue to relax, you will notice the breath in the upper back will seem to fill more and more downward while the breath in the lower belly seems to expand upward."