This update will be rolled-out OTA, so all you have do is wait for the update notification to show up on your Atrix.
Update Details:
System version: 4.5.141.MB860.ATT.en.US
Android version: Gingerbread 2.3.6
Baseband version: N_01.77.37P
Webtop version: WT-1.2.0-110_OLY-6
Kernel version: 2.6.32.9
Build number: 4.5.141
Change-log:
Security: Implemented latest Google Android security fixes
Stability: Improvements to memory function as it relates to media applications and ability to prevent need for re-booting when phone is impacted by heavy loading or high temperatures
Bluetooth: Enhancement which allows you to launch voice command from bluetooth enabled headset when phone is asleep
Wi-Fi: Improvements to Wi-Fi settings to deliver better overall consumer experience as well as to make it easier to use Mobile Hotspot with your phone
Messaging: Improvements to text messaging capability to deliver better user experience
Contacts: Improvements are made to maintain all phone book contacts after the OTA upgrade
More on the update at this webpage | Via
