Getting lean is not that hard, but it needs discipline:
3 Workouts a week - is needed that the body can't shif down on calory usage.
Restrict to 1000 calories a day. Eat 5 meales. Try to get 100 grams of protein a day and carbs should only come from veggies. No wheat, potato, corn or fruits.
And most important: count calories and prepare maeles a day before.
This is a big one. I didn't do this and needed to grab anything close for my meals in the office and it was usually not great things to eat like chips, crisps, sandwiches etc.