I made the switch. Not intentionally; it just kind of happened. I think there were a lot of things that made it work, like taking up running (in the mornings), avoiding stimulants, and good sleep hygiene. But the one that finally made the difference surprised me: it's that I'm not a responsible lightswitch user.

I built an automated lighting system such that dawn in my house comes at 6 am and gets gradually brighter. In the evening, it gradually dims, going out entirely at 10. As long as my ambient lighting is the only thing on in the evenings, I reliably go to sleep between 10 and 11 pm. But if I leave my non-automated task lighting on, I don't get sleepy until hours later, which easily can lead to me falling back into night-owl mode.

I avoid that because my mood is much less even when I'm a late riser, so I'm not advocating that anybody necessarily follow my approach. But if people do want help going to bed on time and getting up early, I strongly recommend automated ambient lighting in key rooms that mimics a natural day-night cycle (but with little or no seasonal variation).