Hi there
I opened in Photoshop, checked the 'channels' to see which minimised the damage .. red/green/blue. I chose to use the red channel and converted to greyscale.
I made a duplicate of the image in layers and used that to work on. Levels were corrected before any other repair work. It helps to identify unwanted marks.
I ran both the 'despeckle' and 'dust and scratch' filters before using a mixture of clone at 40% and healing tool to repair scratches and spots.
There is a line running over and through the man's left shoulder and not much room for repairs on his face, so it was more a matter of breaking the line so it became less noticeable.
When cleaned up I checked the levels again and ran 'smart sharpen' filter.
Wishing you well,
leanan`si