You can’t decide to become selfless, you can only see that the self never existed in the first place. Deconstruct ego by seeing the way that it is built. The five skandhas, the twelve links and other Buddhist teachings are ways to look at the structure. Sitting meditation is away to observe outside of any belief system. See what the energy of hope and fear is. Eventually you see that there is no solid self. If you see the construction, it deconstructs itself.

https://www.youtube.com/watch?v=cW7Lllvsc0k