Open the image in your photo editor and zoom in on your obstruction. Select the Clone Stamp tool and set the pixel size of your brush to a manageable size. Reduce the opacity to 50 percent - the cloning process will take longer but will be easier to control, and the results will be more realistic.
Hold down Alt and click on the background just next to your obstruction. This will set the target pixels that will be cloned. Now repeatedly click on the nearest part of your obstruction until it blends into the background. Simply repeat this process, changing your target pixels each time part of the obstruction disappears.