In typical fashion the update is rolling out in phases beginning today and is expected to be completed by March 9th. We have read conflicting arguments on if manually checking for the update really does any good or not. It doesn’t hurt to try, right? Head into Menu > Settings > More > System Update> Update Samsung Software > Check Now. Be sure you have ample charge on your device, a solid Wi-Fi connection and some time for the update to download. If you do happen to pick it up let us know in the comments. Particularly the file size as Sprint failed to mention that one.
Source: Sprint / Samsung via AndroidandMe