In trying to transcend the ego into cosmic conscious-ness and union with Spirit, I used to think that the ego was a separate "entity" that imprisoned the soul and eventually the ego relinquished its hold and freed the soul. However, after reading a portion of the Bhagavad Gita it seems that the ego is actually the soul dreaming in delusion (maya). I am wondering what is the actual description of the ego since it is the very essence of what I must transcend but cannot picture it accurately.
Defining the ego precisely may be less useful than it seems (at least to the intellect). One value, however, of viewing the ego as the sou'ls (partial) mistaken identity is to help us break down what seems like an impossibly large chasm between where "we are" and where Infinity (or Oneness) exists!
Beyond that encouragement, however, the more practical approach is to develop devotion for God (in whatever form you hold sacred: guru, deity, Light, Peace etc). Our concentration on God or one of the divine attributes will more surely transform and reawaken our divine memory and identity than any mental constructs. What we "see" and identify with, we become. To paraphrase the Bhagavad Gita, he who sees only Me is dear to Me and I come quickly to him.
If it is, however, helpful to clarify who this ego is, consider how our thoughts, emotions, and actions relate so completely around the centripetal energy called "I." Every thought, much of our speech, and too much of our actions are effectively an affirmation of "I" in contrast and distinction from others, our circumstances, in reaction, attraction, and repulsion to objects of the senses, thoughts, memories, and emotions.
Thus working on every desire or fear can take countless lives, whereas gaining awareness and control of our reactive processes goes to the "heart" of our self-affirmation. Remaining non-attached to outward circumstances we gain in clarity, wisdom, and even-mindedness. This process is greatly helped by advanced pranayam techniques such as kriya yoga.
Yet the process of overcoming desires and attachments is the first stage and indeed no guarantee that our ego has expanded into Infinity. That’s the next and greatest battle. In theory, even reason and common sense can teach us to become "stoics" and transcend attachments and emotions. But stoicism cannot by itself expand our ego back into soul consciousness.
This is where we come back to devotion, aided greatly by the practice and science of pranayama. Offer the little self into the great Self of All, at the feet of the Lord, and at the altar of Infinity. From joy we have come, for joy we live and seek, and into Bliss we merge back to God.
Joy to you,