Dear Marek -
a) In the 3rd post in this thread, you stated that you were new to Photoshop. I started using it in 1994, and have used it almost daily since then. To "fix" your photo, I used much of the knowledge and many of the skills that I have acquired in the past 20 years. In addition to the strictly button-pushing, slider-sliding steps, my "fix" to your photo involved completely manual steps such as using a Wacom tablet to smudge parts of the image in such a way as to further enhance a basic cylindrical shape. Even if I sent you the exact Photoshop file that I generated and tried to explain every single step in it, there is no way that someone who is new to Photoshop is going to be able to reproduce the steps, and certainly will not be able to do so on a different starting image that may seem similar, but which actually requires different techniques.
If you truly want to learn Photoshop, you should take much smaller, well-defined steps, practicing each skill in turn before you attempt to use all of them at once on a difficult starting image. Everyone here will be happy to help you to learn in this manner, but I suspect that very few will be interested with what is almost certainly a very difficult task for your at your current level of knowledge.
b) In addition, when I asked why you are requesting this help, you replied: "It is for selling purposes". Also, the title of the thread used the term "Silver Jewelry". From this, it sound like you are not trying to sell the "fixed" version of this image as a work of art or as part of another artistic endeavor (eg, an image in a computer game), but more likely want to sell the jewelry itself.
As I suggested in my previous post, doing such major Photoshop work on an object to be sold has me worried that you will be accused of misleading your customers by misrepresenting the objects to be sold as being in better condition than they really are. I will not help out with this.
Sorry,
Tom