Motorola is rolling out Android 4.1 JellyBean update for the Droid 4, Droid Razr and Droid Razr Maxx as we write.
To do a forced update go to Settings >> About phone >> System updates. Please beware if you are rooted you will loose root for a sure. Our suggestion, wait for the guys at xda to provide a zip file which can be applied from recovery without losing root.