I cannot understand why there are so many views of these questions, with no replies.I have never seen tutorial. The method below, however, while tedious, is always completely accurate and is quite satisfactory for careful viewing.I suggest using clone tool in Photoshop, cloning from as close as possible to flaw; in case of sky, be very careful not to have cloning point any higher or lower than flaw. Any remaining evidence of flaw can often be airbrushed over, using a rather transparent setting f...