It won't happen at the gym, you already exercise everyday, by adding more, you might actually gain weight. It will happen in your kitchen, your pantry and will depend on what you buy and put in your mouth.
You need to eat less and eat better.
Clean your pantry and bin all the crisps, biscuit, chocolate, go for real food, big salads made of sliced cucumber, tomatoes, onions, parsley, olive oil. Have chicken or turkey breast without sauce cooked in a pan or covered in herbs and pepper and baked in oven, white fish, boiled eggs, soups, ....
Avoid snacking totally. If you must, stay away from chocolate bars, even diet or diet sodas. Have some frozen berries (blueberries, raspberries) or an unripe green pear.
make salad with fennel, or celery, go dark green with spinach, broccoli
BE careful about the drinks. Avoid anything with sweetener, smoothies, juices, .... drink water or hibiscus if you fancy a fruity taste.