your text gives the answer! 09:23 Dec 16, 2011
"la remise à niveau cosmétique" is defined in brackets afterwards in your original. It means "rénovation cosmétique" in other words 'as good as new'.
It might be a good idea to give your text a thorough read and consult ordinary online dictionaries and web sources. All of your questions can be answered quite easily in a couple of minutes as they are terms which form part of everyday vocabulary in the context of mobile phones.
Might I suggest that you put your terms into Google images to see first what is being described and then I am sure you will have no difficulty in finding the right word in English.
It is expected that before posting a question, dictionaries and online sources have been consulted. | 
The translation workplace 
