1. Possibly via a "sacred word" in a designated timeframe of perhaps 20 - 30 minutes of centering prayer, this is a model of surrender of oneself via gentle release of all of one's thoughts as they occur. Bourgeault connects this to the famous kenosis (emptying) of Jesus as described by Paul in Philippians 2. Earlier in the book, the author importantly mentions that the release process is very gentle.
2. Establishing some kind of inner "breathing" in this surrender (?) means that "good" and "bad" meditations are done away with. Some will involve more thought-surrender than others. It also involves "releasing the passions and relaxing the will".
3. Over time, the sense of self steadily relocates itself outside the insatiable attention draw of thoughts, a new "magnetic centre" that expands out of meditational times into a more contemplative and larger and deeper self. This doesn't do away with the "egoic" self. Training and moving out of it is all part of the process. This GPS (God Positioning System!) realigns our outer and inner self, the inner being characterised by "your yearning for God and God's yearning for you". Bourgeault connects this new centre with the authentic heart of our person, a deep connection with God's own true heart.
4. This is the goal: to nurture this heart. It differentiates centering prayer from other prayer methodologies which are more focussed on clarity of mind in favour of a singleness of heart.
5. This is not preparation for relationship with God, but relationship with God itself with real psychological outworkings. Divine therapy - centering prayer encourages psychological healing as unconscious emotional baggage is slowly released.
6. The earmarks of this journey are "compassion, humility and a growing equanimity". The whole approach creates enhanced inner harmony. A key word for Bourgeault in this book is "consciousness", and she reminds us of it here: growth toward "unitive" consciousness.
While I hope this super-brief summary might be of help, I highly recommend reading the book cover to cover for yourself. Some of Bourgeault's teaching on Centering Prayer can also be accessed via YouTube (Part 1 here), and she also works with Fr. Richard Rohr.
NB: I have omitted one of Cynthia's own bullets completely. I also failed to fully grasp her description of one of her stages of the meditative process whereby we locate the thought, emotion, passion, tension etc within our bodies in order to prepare for its release. I believe this can only be achieved adequately via experience.