The problem is that I used your sample image to demonstrate! The technique I used on the sample image may not be what I would use on the actual PSD file. Since I don't know how you have your PSD file's layer's panel set up, I can't really offer you a detailed tutorial.
But the general idea is a gradient layer.......
........with a layer mask.
The trick to the highlight is to make your inner selection for the layer mask of the gradient layer (shown above), to include part of the markers. Also make sure you feather your Elliptical Marquee Tool for a smooth transition.