I have recently used this method on my XT926/HD Maxx to successfully unlock the boot loader. I was running 4.1.2 with root, and now I'm using 4.2.2 XenonHD.
This hack requires root access and a working version of SuperUser, aka 'SU'.
Motorola Bootloader Unlocking
I recently unlocked the bootloader for the consumer editions of Motorola Android devices using Qualcomm Snapdragon processors. This includes the Razr HD, Razr Maxx HD, Razr M, and Atrix HD models. The details of this research have been published on Azimuth Security’s blog.
I have created a tool that may be used to unlock your bootloader. It requires that your device has been rooted and that the “su” binary has been properly installed. By using this tool, you agree to the following conditions:
1. You understand that using this tool will permanently, irreversibly void your device’s warranty.
2. You understand that it may not be possible to “relock” your device’s bootloader after unlocking using this tool. A side effect of this is that if you lose your device and you are not using disk encryption, a malicious party who acquires your phone may be able to extract all personal data from the device regardless of any lock screen.
3. You agree that I am in no way responsible for any damage to your device as a result of using this tool.
The tool may be downloaded here. It may be used as follows:
1. Extract the entire contents of the zip file.
2. If you are using Windows, ensure you have installed the latest Motorola USB drivers available for your phone.
3. Ensure your device has been rooted and you have a working installation of “su”.
4. Ensure USB Debugging mode is enabled on your device.
5. If you are using Windows, navigate to the extracted directory and execute “run.bat”. If you are using Linux or OS X, navigate to the extracted directory in a terminal and execute “./run.sh”.
This process is quite painless and takes only a few minutes.
Neither I nor Dan guarantee this will work and that you will not brick your device. Proceed at your own risk.
Read all the instructions before you proceed and make sure you understand the process before you follow through.
He does have a PayPal donate button on the webpage and I urge anyone who uses this to donate to him. This opens up the doors to so many people that were otherwise left out of the mod community.