I want the body I once had. Abbs and all

Yup thats right I want my old body back. Over the last couple of years I have put on some pounds, well more like a spare tire around my waist. I now work a 15 hour day at a desk. Yes I do blame my work for it, as I am no longer active. I make much more money now, but I was in much better shape and happier with my body when I worked retail and made half the money. I would like to at least lose 15 pound by June….I am standing in a bridal party and we have to wear a little black dress. One in which my spare tire sticks out like a sore thumb. Does anyone have any excersie programs that you can do at home?????