The update will trickle around the globe slowly with it starting in the UK. Samsung has the update available for manual installation vie Samsung Kies, but a traditional OTA is also being rolled out. Of course updating through Kies will prevent you from having to wait very long for the update.
As always, don’t forget to have well over 50% charge on your device before doing any firmware updates regardless if it is an OTA or through Kies. If you are able to snag the OTA, then also make sure you have some time to kill and a solid Wi-Fi connection.
Source: SamMobile