The replacement process is available in your country as of 2nd May 2014.
Bring your iPhone 5 to a participating Apple Authorized Service Provider. Your iPhone will be examined to verify eligibility, before proceeding with the replacement process.
Note: To use the carry-in option, you must visit a participating Apple Authorized Service Provider and not a wireless carrier partner.
Preparing your iPhone 5 for service
Make sure your iPhone is ready for service by completing the following steps:
Back up your data to iTunes or iCloud
Turn off Find my iPhone
Erase data and settings in Settings > General > Reset > Erase all Content and Settings
Remove any case or cover
Note: If you are running iOS 6, your iPhone will need to be upgraded to iOS 7 after the sleep/wake button mechanism is replaced.
Additional Information
Apple may restrict or limit repair to the original country of purchase.
Your iPhone 5 must be in working order to qualify for this program.
If you believe you have paid for a replacement due to this issue, contact Apple regarding a refund.
This worldwide Apple program does not extend the standard warranty coverage of the iPhone.
The program covers iPhone 5 models for 2 years after the first retail sale of the unit.