I can relate a bit. I was 90kgs while working, now at 70kgs.
Sustained calorific deficit is the only way. Diet and exercise.
(1) Walking. Do a lot of walking. Walk while talking, while working if possible. It burns calories left and right.
(2) Calculate your maintenance calorie requirement and use HealthifyMe to stay 10% below daily required calories.
(3) Have 1 cheat day a week where you eat maintenance level (or even 10% above). Prevents your metabolism from getting used to lower calories and keeps your calorie burn rate high.
(4) There’s no such thing as burning fat away from certain areas. Just focus on losing weight and you'll be good.
(5) Introduce more protein in your diet (soyabeans, beans, rajma, etc.) to prevent muscle loss while in calorific deficit. You want to lose excess fat not muscle so lifting some weights daily for 10 mins goes a long way.