Removing scratches off jewellry, where to go?

[FFGFG]

I heard from quite a few people that some jewellry places can remove minor scratches on jewellry - metal, stainless steel, silver, etc. Where would I go for this and what exactly do they do to it? Hope its not an expensive process.

THanks, looking to get this done pretty quick as soon as I find a place that does it. Its just a few minor marks, nothing deep or banged up.