The carrier confirmed the update is pushed OTA (over the air)
US Cellular launched the Motorola Electrify M last year in November with Android 4.0.4 Ice Cream Sandwich operating system onboard.However, Motorola Mobility promised a Jelly Bean upgrade will be available for the Electrify M sometime in Q1 2013.
According to AndroidPolice, the update is now live for all Motorola Electrify M owners. The US-based carrier even posted the announcement on its support website so those who purchased the smartphone learn how to download and install the update.
Keep in mind that Android 4.1.2 Jelly Bean is pushed through OTA (over the air), so make sure the phone is connected to a stable Wi-Fi network.
Motorola Electrify M users who have yet to be notified on the update can manually check for it by going to Settings / About phone / System updates.