Ah yes, fatherhood will change a night owl. I've made the adjustment for the same reasons, went from sleeping 4am-10am to 930pm-4am (extra half hour sleep!) and while the first two weeks are rough, it's been smooth sailing since. You can do it. The 4am-6am is just as magical as the 2am-4am was for me. I'll skip breakfast until after 6am so I can jump right in it.

That being said, I still plan on going back to being a night owl when the kids are grown.