Hate the belly fats

Overall i look slim, but i still have a flabby tummy. Can anyone out here tell me what is the best way to lose belly fat? Exercise? Diet? Pills? I hate exercise and i can't have either diet or pills now because i am still breastfeeding my baby. I have bought myself a skinny leather pants, so i sincerely wish i can lost my belly fat before Christmas, if i do, then i definitely can show off my new leather pants to my friends.