You don't really make a switch from being a night owl. I thought I'd made switches multiple times too:
* Taking early classes in college * Deliberately cooling myself down and going to bed super early * Getting a puppy that forced me to wake up super early
Every single method regressed to night-owl schedule within 2 months. Not to mention my productivity and learning ability took a nosedive during the periods I was waking up early.
This is over a period spanning 15 years, so it involves multiple stages of life as well.