Best way to do it and keepp with it is to start small. Baby steps stick more than overnight lifestyle changes.

Drink pop? Quit drinking pop. A week or two of that, tell yourself no more fast food. Decide to go on a 30 minute walk twice a week just up and down the street, and slowly transition it into more and more exercise. Plunging into it all out right away might sound like a good idea but you'll surely burn yourself out that way.

I know you can do it.