1 word bro: Bowflex.
Seriously, if you lost 10 lbs (which is possible in 4 weeks) you would be at 10-11% BF. Add a diuretic, and your set.
Go on an extreme pre-contest diet:
This was my last diet: (I weigh roughly 200lbs):
Meal 1: 20g of whey (Bcaa's would be better)
Cardio: 40mins on a treadmill 70% of max heart rate
Meal 2: 2 eggs, 45g of whey, 20g of oatmeal
Meal 3: 2 chicken Breasts, 1 slice of whole wheat bread
Meal 4(pre-workout): 10g of Raw Honey, 25 g of whey
Train: High Volume(20 sets), supersets, 10-12 reps per set
Meal 5(post-workout): Powerade, 25g of whey.
Meal 6: 40g of egg/milk powder, 20g of oatmeal
Meal 7: 1 cup of Black Beans, 2 cans of tuna, 1 tablespoon of olive oil
Meal 8: half a container of no fat cottage cheese.
Total: 160g of carbs, 320g of protein, 50g of fat.
On non-training days, lower carbs to 120-130g
Add some clen, winny/anavar/fina/T3, whatever, and you are definetely going to lose 10 lbs if not more.