Title says it all, is it possibe, im at 82kg now and want to get to 79kg in 4 weeks,

how do i go about this, diet food, workout, ect...

Combine, dine, you' ll be fine.

Cut out sugars (refined sugar completely). Eat fruit when you want something sweet. Stop adding salt to food. Eat no bread. Drink only water when you want something. Do a bit more skipping and running than usual. Don't eat after 6 if possible. Don't fry your meat; either boil, steam, or roast it in the oven with no salt nor oil. You follow this diet, along with hard work in the gym, and you'll lose weight in no time.

I would imagine this would work for you unless you're eating perfectly as it is. In that case, just fight at your natural weight.

Good luck tricky.