"Lie on your back, place your hand on your stomach, focus on your breathing ensuring that you expand your stomach on inhalation and contract it on exhalation. Do not concentrate on any specific thought(s). If your mind starts to wander, acknowledge the thought(s) and then let it go. Do this for 30 - 60 mins a day.".
Discipline is required to do this, something I am terrible at. Either I feel like I am wasting time or I fall asleep. :D
As far as I've learned & experienced, meditation is always practiced sitting upright - it's actually a quite important part about it. Like that: http://www.google.at/images?q=mindfulness+meditation+posture...
Much of the book is has him discussing his pain & wellness center, patients & his own life. Which is why I said it's wordy. I have read reviews that suggest his follow-up book has more meat & potatoes on meditation techniques:
http://www.amazon.com/Wherever-You-There-Are-ROUGH/dp/140130...
*Yes there are exception to this which my logical mind started going down, such as paralysis, death, drowning, choking... etc...
however personally i've experienced meditative state most deeply lying flat. YMMV and i haven't read that book.
It can be summed up even shorter than you're describing ... but it's fucking hard to do, unless you have strong motives to do it and belief that this practice will have a good ROI on your mind / body.