Duplicate the layer with the image and play with the color curves untill you're satisfied with the result.
You can easily see the feathers now. After you rendered it(working on the original layer, not on the one with edited color curves), take a fuzzy brush on low opacity, zoom in a lot, and start erasing the white parts near the feathers. This will also make it look smooth and fluffy. This is the basic method. There are other ways of doing it with layer masks or quick selection.
Thii will be your result but hopefully better cause you'll notice the many flaws. I did this in 5-6 mins so ofc it needs more time and effort.