Make a selection with a good deal of feathering around the glare, and then ad an adjustment layer, using the selection to define the layer mask. The adjustment type is what you prefer. I would start with Levels or Curves, but things like Brightness/Contrast work too. You can refine the mask, and change the Blending mode and transparency as well.
Two things about glare: It's usually a different color balance from the surrounding area. A good portion of it is likely to up near the highlight clipping point, so you can't get a lot of nice detail from them.
Often, it's better to leave some of it, just toned down a bit. If you go too far, it can start looking fake, or at least obvious.