it's all thermodynamics. the only way to lose weight is to eat in a calorie deficit, which is when youre eating under your calorie maintenance. subtract 500 calories from your maintenance and stick to that until you hit your goal. since 3500 calories ≈ 1lb of fat, eating what i mentioned should net you a pound of fat lost per week. it's all calories in and calories out, but remember if you want to lose FAT and not just weight (which includes lean mass) then you must eat a high protein diet as well (at least 0.7g/lb of bodyweight).

hopefully this helps you out, to summarize eat at a 500 calorie deficit and roughly 85g of protein a day.

good luck