I added the grass several times and blended it, to make it look like one big field. I also enlarged the image to the side, with using the clone stamp tool for the sky on the right side of the picture.
I added the path and blended it with a soft big eraser.

I cut out the hourglass and placed it on the background. With a soft eraser with opacity set to 10, I erased the former background so far, that the wood texture wasn't visible anymore.
I copied the sand, the reflections and the running sand from the original source and placed it on the new one. I can't show the single steps, because I merged those layers and noticed it too late... *sigh*
I desaturated the two big reflections and lowered the opacity to achieve the same look as in the original.
Furthermore I changed the colour via Hue/Saturation to blue. I did that twice, once with a lighter blue, the other time with a darker blue. I lowered the opacity from the dark blue layer, so it doesn't really effect the sand colour, but it makes the glass look more "glassy"

I added the two animals. I shortened the legs from the horse and warped the front right leg, so it hangs down. The parts in the back from the horse I painted over with a similar colour to the one the sky has. Unfortunately there were parts from a house before.
I also added the tree textures to make it look less like metal.

I changed the colour from the statues via Hue/Saturation and colour match and added the hour glasses. Also some dodge and burn to fit the light source.

I added the barbed wire and the leaves. The colour of the leaves was again changed with Hue/Sat. I erased some parts here and there to make all look different.

Finally I added a dark yellow photofilter and an extra layer with gaussian blur and blending mode set to soft light.