I found a way to force the OTA Update for Jelly Bean. Its actually quite simple, and it worked for me pretty quickly.
Step 1. Go into the settings menu on your phone and open the Application Manager. Now select the tab to see ALL of the applications
2. Look for "Google Services Framework" and click on it.
3. Press the Clear Data button, then click Force Stop, this will not hurt your phone or anything on it so dont worry! (If any of you are wondering about the Google Service Framework data clear, this is done because the Android update is sent out by Google, so when clearing the data and doing the force stop, it basically refreshes the current state and status of that service, which in turn makes your phone basically look for any updates.)
4. Now go back to the Setting Menu and go and to the System update area and go to Update Samsung Software. The date at the top where it says "Date last checked" should be something like 12/31/1969, which means your phone is now prioritized to recieve the OTA Jelly Bean update message.
5. Click the Check now button to check for the update again, your phone should recieve the update message. You might have to go back and repeat this process a few times, clearing the data and forcing stop, I was only pressing clear data first the first 2 times I tried this, and checked for the update and nothing happened, but then when I went back pressed the force stop button for Google Services Framework, and re-checked for the update I got the update right away.
http://www.ijailbreak.com/how-to/force-ota-system-update-android-phone/ <---- This is the website I found saying how to get the Update.
and this is the screen you should get after you press Install now after recieving the update
Ok as long as you didn't think you still had Ice Cream Sandwich...
I think the 4.1.2 update is only available internationally. I could be wrong but I think Samsung has to send Sprint the update first, then we have to wait for the OTA. While we're approved to wait on the OTA, THEN we can probably force it...