500 pieces?!...whoa. Don't break it apart, man LOL. More than the only thing you need to change is the front and back plate. When you take out the battery cover, there will be 2 screws, unscrew those. Then move the backplate slightly up and outward because of the clips on the top of the backplate. Afterwards, just concentrate on the front plate.
If you're uncomfortable with taking the phone apart yourself, then bringing it to a person or business that has experience would be the ideal decision. Just remember, removing the housing will void the warranty.