Of course it's always better to get a good image to begin with rather than to repair a bad image, so to get rid of specular reflections you should use the well known technique of crossed polarizers. Put one in front of the light, and other in front of the lens and rotate it until the specular reflections go away.
Let me know if you are unwilling or unable to get a good image to begin with by using the method I highly suggest trying, and I can let you know of worse, inferior techniques to try to remove them in software, but post processing in software should NOT be your first line of attack.
