SHV-E120S how to update to 4.0.4
What I did is to first use the ODIN to install the rooted kernals (you could find in XDA links). Use the standar ODIN procedure and clear the cache.
Then use the market enabler app to set your region to S.Korea. As the market enabler need to have a root permission.
Make sure that once you set this, you do not open the Google play or do anything, other than connecting to Kies.
Kies will show you the latest update for your device, go ahead & update. Welcome to ICS.
I used the ODIN to move to a rooted kernal since any root procedure in the internet was not helping me to get the phone rooted.
PS: Try at your own risk. Though I do not see any problem to happen in between other than the ODIN flash. I suppose I took the rooted tegrak kernal.
Also one more tip, if after the root Kies is not detecting the phone, try the procedures to un-root the phone & retry.