I need to change my sleeping schedule. Any advice?

I am a natural nighthawk. I currently sleep around 5 am (don’t go there) and need to start sleeping @ 11 pm which is 6 hrs earlier of course. I do exercise everyday and I don’t have insomnia or falling to sleep problems. I just DON’T sleep because I want to read a novel or be on the computer etc. It’s probably not smart to go straight from 5 am to 11 pm, so I was thinking of doing it in baby steps. I also need to wake up @ 6:45 am, and I have trouble waking up on time, let alone early. I often don’t even hear the alarm. I want to change my schedule as a personal choice. If you have any advice or had to change your sleeping schedule like this, I would love to hear about it! Thanks.