Spiritual Transformation is simply a shift from unconsciousness into a more conscious state. You are more aware of yourself and what the real World is rather than what you were taught to believe it is.
These Transformations can be simple or profound, they can include spiritual awakening, becoming a parent, changing your diet to come into alignment with your body, and much, much more.
It does not have to be major, but sometimes once you get started on this spiritual path, things start moving on their own.
Meditation is a way to start to get to know yourself. Spiritual teachers and sacred spiritual texts can also assist your spiritual Transformation from someone who is lost in ignorance into someone who is wise and at peace.
The most important part is cultivating your inner knowing so that you feel what is true for you rather than just accepting whatever anyone else has to say or living only the ideas that are convenient to your current ego beliefs.