You can use the clone tool and set the blend mode to color, next to the brush thumbnail in the upper bar. You will probably still see some greystripes, but the parts that go unnoticed after removing the color keep you from doing too much stamping. Try the healing brush for the parts of the remaining lines that go over the ground. I suppose the parts that are still visible on the soldiers and such need zoomed in cloning tool work, with a small brush size, a relatively low opacitiy and a lot of option-clicking to use different parts as a source (a Wacom pen is nice to have around for subtly 'painting' away stuff, because you can handle the opacity by pressure) to prevent repeating paterns and visible repairs. Good luck! BTW I hope you have a much larger file to work on then this jpg, size matters, in this case.