I need help
You will be better off working on your RAW file. I can't give you numbers because I don't have any (that you could use) since this edit was done with Pixelmator.
I duplicated the layer. On top layer I colour selected the cyan ring on his forehead. I extended the colour selection range to include the cyan halo around his face and the in his heir. This range of-course includes lots of areas in the image but for that parts I could mask the layer and use the original layer instead.
I then used the hue - saturation and luminance tools to change the cyan to a colour of its proximity. It was done with trial and error. but I think I improved it somewhat.