The glass pieces on the back of the iPhone 5 aren't serviceable... at this time. Your only option is to; A) pay Apple for a replacement, B) replace the entire housing yourself (I see them online going for around $100-$150 USD), or C) add a colored vinyl overlay to the affected area (your cheapest option by far... plus you can customize w/ many different color options.) We have two Supporting Vendors that offer such products...
GrafiXpressions.com &
SlickWraps.com .
