Soon after Motorola revised its software upgrade timeline, changing the original Atrix 4G's ICS ETA from Q3 2012 to a disheartening "further plans coming soon," a leaked Ice Cream Sandwich build has cropped up on XDA's forums. If you're the owner of an Atrix 4G and you're tired of waiting, there's good news - the leak, which carries an August build date, can be downloaded and installed on your device in just a few easy steps. Here's how it's done:

Disclaimer: Android Police isn't responsible for any harm to your device - proceed at your own risk.

Step 1.

Download the .zip here. If you haven't already, grab the appropriate Moto drivers here, and grab the MOTO-FASTBOOT application here.

Step 2.

Reboot your Atrix to CWM and wipe data and cache. Then reboot into fastboot, and connect it to your computer with a USB cable.

Step 3.

On your PC, open a command prompt (cmd) and navigate to the directory where both the leaked zip and MOTO-FASTBOOT app are located, and execute the following commands:

moto-fastboot.exe flash boot boot.img
moto-fastboot.exe flash preinstall preinstall.img
moto-fastboot.exe flash radio radio.img
moto-fastboot.exe flash system system.img
moto-fastboot.exe flash webtop vendor.img
moto-fastboot.exe reboot

Step 4.

Wait a few moments for your device to switch on (this part may take a while), and enjoy!

So that's it. Many users over at XDA are reporting success, though your mileage may vary. To keep up with the conversation, just hit the link below to see the original XDA thread.

Update: And it's gone. The thread over on XDA, as well as the .zip on dev-host are no longer available.

Thanks Dave and aa!

Thanks to Rhadamg and Epinter for instructions!

Source: XDA Forums