I need to wake up at 4AM in saturday.

I have an appointment at 5AM at my school that day, and what I'm going to do there will give me some sweat.

This is my general sleeping habit: go to bed around midnight~1AM, wake up around 8.

What should I do to increase a chance of waking up at 4AM? Relying on alarm from my cellphone alone is not a good idea. I've got 2 suggestions so far.
1. Don't sleep tonight, and go to bed early tomorrow.
2. Sleep normally tonight, do hard excercise on Friday's evening, e.g. do 3 football field's laps of running, then go to bed early.

At the time I post this, it's 0AM of Friday. And no, I'm not taking sleeping pills.

Do 50 pushups before you go to bed, and put 1 or 2 alarms away from your bed, so when they go off you have to get up to turn them off.