Now that the unlocked version of the Samsung Galaxy S II has received Android Ice Cream Sandwich, its time for the carrier variants to get a taste for the latest Android treat.
So if you own a Samsung Galaxy II on Vodafone you are in luck as Android 4.0.3 Ice Cream Sandwich has just started rolling out for your devices.
You should receive a notification when the update is available for your device. If you don’t recive the update notification feel free to manually check for the update availability.
Once the update is available connect your device to your computer and update using the Samsung Kies Software.
source - Vodafone