Your attention is either on your thoughts, or it’s on the rest of the present moment — the sensory world of sights, sounds, smells, feelings and tastes. There’s really nowhere else for it to be. So living inside your head less amounts to living in the physical world more. Sometimes the world around us is just so damn beautiful that it rips your attention away from your thoughts, but the rest of the time you have to put your attention there manually.
It’s not particularly hard to do that, but it’s definitely hard to remember to do that. It has to become a habit, because Living in Our Heads Without Realizing It is something we adults are better at than almost anything else. But becoming present can become a habit if you do it often enough.