You can google "how to fix your sleep schedule instantly" or "how to reset your sleep cycle" and get a LOT of good tips.
I'd recommend exercising a lot during the day so you can get tired faster, create a proper night routine, stop everything one hour before the time you want to go to sleep (and have in mind the time you want to get up at), if possible get some vitamins or melatonin, stuff like that.
Anyway, make sure to Google to reinforce what you have in mind.