As a student, I have experience with fucked over sleep schedules. Also I am a night owl who used to play too much with Americans, and basically adopted their times during the week, then switched back to European times in the weekend (that's a 6-8 hours difference). So to give my two cents on how to fix your sleep schedule:
If it isn't too fucked up, as in I am going to bed around sunrise (which is ~6'ish hours off), I will tend to sleep only for around six hours, which usually has me wake up around noon. Then you can easily go to bed again at a normal hour right away, or perhaps a tad later and sleep a few hours less. Either way you should be able to wake up at a decent hour the next day. This definitely works best for me if staying up late was more of an exception, because that means I was awake for an entire/half day + night, so a short sleep is enough to get me through the day but not enough for me to not be tired at the end of it.
Basically you turn a 24 hour day into an 18 hour day: 18'ish+ hours awake fucks up your schedule > sleep 6'ish hours > awake 12'ish hours > go to bed when tired and wake up at a 'normal' time. Instant fix.
If it is more of a repeated thing that I am staying up late, or I really am sleeping when any normal person would be awake and vice versa, then it usually is easier for me to 'skip a night', aka on five days/four nights, I will only sleep three times. Usually this involves me staying up late (past sunrise), go to bed and sleep until it is evening, get up and stay up until past noon, sleep until past midnight, go back to normal schedule. Note that this may be harder for you if you aren't the type that can stay in bed for 12 hours, as that means staying awake much longer than usual.
Basically you turn a 24 hour day into a 30 hour day which moves your sleep schedule up 6 hours every day until you can get it somewhat right again and go back to normal. Takes a bit longer than instant fixes, but I find this works better if you are beyond instant fixes.
Also, protip: sleeping less than 6 hours usually isn't worth it and you are just making yourself feel more tired while fucking over your rhythm. Sometimes you don't have a choice because very busy days (aka work until 1am, have to be back at work the next day at 7am or so), in which case you should grab whatever sleep you can. Usually you have a schedule then anyway that is going to keep you from fucking over your sleeping rhythm, just don't do it regularly.