In the past I’ve ham-handed my attempts at flare removal. Some have turned out reasonably okay and others not so much. I recently learned a method involving an inverted curves adjustment that does a nice job. Of course, this image is fairly clean so less challenging than others might be. But at least for a first attempt I am pleased.
Mount Monadnock in New Hampshire from The Patten in Shelburne, MA. May 2015
Can you see where it was?