In the glare the image is totally burned out (all three channels maxed out), so you best bet is to reconstruct the letters (which, fortunately for you, are mostly straight lines).

I would do this (Gimp or PS) by creating a path that outlines the missing bits and overlaps the remaining ones, getting a selection from that, and apply a gradient:

• The blue line is a path that marks the base line of the letters, useful to tell where the foot of the Nand T are.4
• The red line is the path that makes the outline of the letters
• The white line with + at the ends marks the gradient

This is a quick hack, but if you draw the gradient on separate layer, you can play with local opacity to make it blend a bit more naturally in the original image.

Alternatively you add the Uand the other T in the processing to remove the glare on them.

Edit: for a slightly cleaner and more natural looking result:

Insert a layer and clone a non-glare area to fill the overexposed glare area: