Macbook Keyboard Cover Cleaning?

I recently got a Macbook Pro 13" this past year and after about a week of use I decided to order a keyboard cover off of Amazon. After a few months of use I took it off to make sure no dust was caught in my keys. Once I took the cover off I found that the keys had glossy spots from my Apple Macbook Keyboard Cover. This discovery was a frustrating one. Is there any way to clean the keys to the original appearance? Please let me know of any keyboard cleaning tricks for keys.