How to Replace iPhone 3G and 3GS Battery: EveryiPhone.com
Replacement Battery For iPhone 3GS used to Replace battery for iPhone3gs battery for iphone 3g battery with open tool - AliExpress Cellphones & Telecommunications
How to Replace iPhone 3G and 3GS Screen: EveryiPhone.com
iPhone 3GS Battery Replacement
iFixit iPhone 3GS Replacement Battery with Fix Kit – RamCity.com.au