I'm not sure what happened to the last tutorial for this, but I put this one together to help others.
The tutorial explains how to add specular highlights capabilities to GMax, and how to apply this to a model in GMax (These settings are also good for 3DSMax). The tutorial also explains how to turn this off as well.
You can find it here:Specular highlights tutorial
It is expected that the user is reasonably comfortable with the GMax interface, knows how to apply basic textures, how to create objects, and is reasonable comfortable with editing files in notepad.