iPhone 4 Important Product Information Guide
Repairing or Modifying iPhone – Never attempt to repair or modify iPhone yourself. iPhone does not contain any user-serviceable parts, except for the SIM card and SIM tray. Disassembling iPhone, including the removal of external screws and back cover, may cause damage that is not covered under the warranty. Service should only be provided by Apple or an Apple Authorized Service Provider. If you have questions, contact Apple or an Apple Authorized Service Provider. For service information, choose iPhone Help from the Help menu in iTunes or go to: www.apple.com/support/iphone/service/faq
Battery Replacement – Do not attempt to replace the rechargeable battery in iPhone yourself. The battery may only be replaced by Apple or an Apple Authorized Service Provider. For more information about battery replacement service, go to: www.apple.com/support/iphone/service/battery