Need help to lose weight while breastfeeding?

HELP! I am trying to lose weight safely while breasfeeding, but nothing seems to working!! i have not lost any weight since having my baby nor have i gained any but i need to lose 15kg to get back to my pre-pregnancy weight. I am not in a rush to this but would love to at least get the weight moving. Does anyone have an eating plan/ excersise plan that worked for them ?? please help me!