Because the sun was shining from the upper left and behind, I darkened the front of the tent, as well as the grill. I removed all the weapons in and around the tent and cloned in and copy/pasted in the empty spaces. The top image is the before, the bottom image is the after.
I desaturated the suit of armor and used brightness/contrast to boost the shine. The end of the lizard fingers were liquified to bend them around the knight. I desaturated the source helmet, matched it to the armor and colored the eagle (?) on top.
I used strips of the pasture photo to widen it, blending the strips together. I didn't bother blending where the tent was, in the grey circle. I then used adjustment layers (brightness/contrast and color balance) to brighten it up. I used gausian blur for the shadow and blurred the sky and grasses for depth.