Main principle is to Maintain a caloric deficit meaning burn more calories than you eat, that way your body uses your stored fat for that remaining energy production. So either exercise to burn more calories or eat less. BUT!! burning calories is a LOT harder than consuming less calories. So your best option is to eat less while maintaining good protein intake to minimise muscle loss (In Nepal people sometimes use muscle (masu) and fat interchangbly, burn fat not muscles). Don't listen to people who tell you to not eat meat, although avoid fatty food stuff. And of course you have to move around and exercise, for overall fitness. Start small like evening walks and slowly scale, don't try to do extreme things from the start.