In 1975, Francesca Freemantle and Chögyam Trungpa published a translation of The Tibetan Book of the Dead: The Great Liberation Through Hearing in the Bardo (Boston, MA: Shambhala, 1975).
In the Forward to this translation, Trungpa places the book in its context:
The Bardo Thotrol is one of a series of instructions on six types of liberation: liberation through hearing, liberation through wearing, liberation through seeing, liberation through remembering, liberation through tasting, and liberation through touching. They were composed by Padmasambhava and written down by his wife, Yeshe Tsogyal, along with the sadhana of the two mandalas of forty-two peaceful and fifty-eight wrathful deities.
Padmasambhava buried these texts in the Gampo hills in central Tibet, where later the great teacher Gampopa established his monastery. Many other texts and sacred objects were buried in this way in different places throughout Tibet, and are known as terma, 'hidden treasures.' Padmasambhava gave the transmission of power to discover the termas to his twenty-five chief disciples. The Bardo texts were later discovered by Karma-Lingpa, who was an incarnation of one of these disciples.
Liberation, in this case, means that whoever comes into contact with this teaching—even in the form of doubt, or with an open mind—receives a sudden glimpse of enlightenment through the power of the transmission contained in these treasures. (p. xi)
As the text says of itself,
To meet with it is great good fortune; it is hard to meet with except for those who have cleared away their darkness and gathered merit. If one hears it, one is liberated simply by not disbelieveing, therefore it should be greatly cherished; it draws out the essence of the dharma. (p. 71)
The University of Virginia Library's Web exhibition on Tibetan Religion and the Western Imagination: Translations and Interpretations of the Books of the Dead provides a context for Trungpa's translation:
Based on lectures presented at his own Buddhist institute in Vermont, the charismatic Tibetan teacher Chögyam Trungpa (1939-1987) published his own edition of The Tibetan Book of the Dead in 1975. This edition exhibits the distinctive quality of Trungpa's peculiar blend of American counter-culture individualism and Tibetan Buddhist orthodox conservatism. His highly individualized commentary to the translation certainly owes a debt to Carl Jung. In Chögyam Trungpa's view the bardo experience is an active part of every human being's basic psychological make-up, and thus it is best described using the concepts of modern psychoanalysis, such as ego, the unconscious mind, neurosis, paranoia, and so on. Indeed, the greatest virtue of Trungpa's text is its ability to convey the messages of the Book of the Dead in a free-flowing and comfortable style unburdened by the specialized and obscure language so often encountered in more academic works.
For those wanting to know more about the author, the Shambhala Web site provides this biography.
The details for the days of the bardo gap (the "between" from death and before rebirth when enlightenment is achievable if the person who has died can recognize the true nature of reality and dissolve into rainbow light) presented here are passages spoken to the dying/dead person, and they are as quoted, with these exceptions: the spelling has been Americanized ("center" instead of "centre" and so on) and the dying person has been generalized to include women [that is, "O son of a noble family" and "sir" direct addresses to the dying person have been removed]. I realize that some exclusion and exclusiveness was intended for the esoteric transmission, but to relate to the content as an individual I needed to cut through that.
Text for each period is followed by explanatory material: relevant glosses from Francesca Freemantle's "outline of the Buddhist psychology," plus Chögyam Trungpa' Commentary as presented in a seminar in Vermont in 1971.
For a bit of personal history, I started reading Chögyam Trungpa's books, including his translation of Bardo Thotrol, in the 1980's after some visits to Dharmadhatu in Austin, Texas, now called Austin Shambhala Meditation Center.
When my mother died in 1987 and my father died in 1993, I read these instructions to and for them.
Sentient beings are numberless: I vow to liberate them.
Delusions are inexhaustible: I vow to transcend them.
Dharma teachings are boundless: I vow to master them.
The Buddha's enlightened way is unsurpassable: I vow to embody it.