Honestly don't understand why you're not used to those hours by now. Just... go to sleep at the same time each morning, and wake up at the same time each day. Your body should handle it fine after a couple of weeks, max. Get outside plenty in the arvo, and have a well lit work area. Make your room dark to sleep in, and I strongly recommend cotton-and-wax earplugs. Those things rock.
Sure you'll lose your weekend mornings, but that comes with the job. If you want to trade those hours, just shift your whole day over and stick to it.
Me, I've just switched my own trading from US time to Europe. Can get the kids from school, eat dinner while I trade, get to bed at a reasonable hour (usually an hour or two after the US open), sleep to 8am, easy. No big task to shift a little on the weekends when I have my kids, get up at 7 to make pancakes. At least, that's the plan - only just getting back into trading after a couple of years out of it.