How does one conquer ego?

What is ego anyway, and why would anyone feel the need to conquer it, or get beyond it? Is that even a good idea?

Let's look at what ego actually is. If we believe we are spiritual beings, perfect within the limiits of our ability, then ego is some kind of add-on. It is not who we are at basic.

I would say ego is our collection of ideas, judgments and opinions as seen through our viewpoint. Viewpoint is simply the means we use to see this universe as a spiritual being. Over time we have used this ego as a means of communicating, of having identities to do stuff, to be someone. At some point each of us likely decided to look through the eyes of a life form to play the game. Then at some point decided we ARE the life form. The life form became our viewpoint and our ideas, opinions and judgements became a part of us. We are not our viewpoint or any of our ideas, or "ego", however. But believing it leads to all sorts of trouble, especially since a life form can be hurt and die. It is possible to become so confused one believes that simple disagreement with one's ideas is a threat to one's survival! Most wars begin over differences in ideas and those who are most dedicated to their own ego are most likely to insist on their point of view prevailing. When ego becomes more important than life people will die for it.

So what do we do about it? A first step is to recognize that one is not one's ideas, or thoughts, or feelings. One has them like a bag lunch. If they can be discaded it is no loss, whether they are seemingly positive or negatve. You can create anything you want on a much better scale than ego.
There are more steps possible, if one wishes. But knowing you are not what you are thinking or feeling is a pretty big one.