Stripping fat

Hi guys

I am aiming to strip the fat off my body and looking for help in doing so. I reckon I need to lose a stone and gain better definition. I am training for a half marathon in March and I do some lifting at the gym. I know it is diet that i need to be careful of and am reducing my grains, I don't think I eat enough protein as I generally eat a lot of veg.

any advice or links would be awesome.