Upload & Sell: On
I dragged the image to PS, selected all, dragged the window by the LR corner to expand the window. Then I clicked on Edit>transform>Rotate, grabbed a corner and rotated it some clockwise. Then I clicked on Select>Inverse to select the corners that the rotate created and used shift-delete to do a content aware fill for the corners. Then I used the clone stamp to clean-up the created parts of the rotated frame and blend the corners.
The result of the above steps created the first layer. To lighten the edges of the modified image I used the lasso to make a selection and used the refine edge to feather the selection. Then I make an exposure new layer using the selection and bumped the exposure to further lighten the selected border area. Then I used a filter layer to add a slight bit more warmth. Finally I made a new layer from the existing layers, used Topaz DeNoise to reduce the shadow gritties, added a little mid-tone bump with USM and used the sharpening tool to slightly sharpen the eye and bill and some feathers the DeNoise had slightly softened.