I would say that I don't know, but as I understand it one cannot change the past or the future as they already exist and always have. This eternal moment may indeed be all that exists, but within it exists all of the possible past and future moments, of all of the many worlds, in all of the many dimensions, and they are all equally real. You can however, choose which of those many futures you experience next, and perhaps even the past that lead to that next present moment (I think it depends on which dimension your consciousness is moving through), by the choices you make in the present moment. Yes, I agree that time as we think of and experience it can be seen as an illusion, but that does not make it any less real, just different than we perceive it to be.