The Droid Razr HD cannot be unlocked using the standard Moto unlock procedure from there website, the only known way of unlocking the bootloader after root is achieved is via Motopocalypse written by Dan Rosenberg and available from his blog site here.
The basic jist of it is from the link above is:
The tool may be downloaded here. It may be used as follows:
- Extract the entire contents of the zip file.
- If you are using Windows, ensure you have installed the latest Motorola USB drivers available for your phone.
- Ensure your device has been rooted and you have a working installation of
- Ensure USB Debugging mode is enabled on your device.
- 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
You may also be interested in the RazrHD Toolkit 5.0 which can automate some of the processes involved, but I generally recommend doing it manually, so if something goes wrong you can see what happens and potentially correct the issue. All in one tool kits tend to mask the processes, which if they work is fine, but if there is a failure it can be very difficult to diagnose and correct.