You are more likely to find answers in the rooting section. Here is link to an answer, copied below, that I posted there:
http://forums.androidcentral.com/ra...root-after-6-12-173-ota-w-o-rootkeeper-2.html
Security Research by Dan Rosenberg
Also, there is a great utility that has 17 contingencies built in that, while a big file, can help plan for the future, including Root for ICS.
This utility does the following:
1. Restore Droid Razr to 6.12.173
2. Droid Root for 2.3.6 (motofail)
3. Unroot
4. Install Voodoo's OTA Rootkeeper App
5. Install Bootstrap Recovery App
6. Install Safestrap Recovery App
7. Overclock install
8. System Pull
9. Droid Razr Root for ICS 4.0.3
10. Boot into fastboot from Debuggin
11. Boot Normally from Fastboot
12. Boot into Motorola Recovery from Debugging
14. ADB Shell
15. Wipe Data/Cache
16. Attempt Bootloader Unlock
17. Reboot Phone
Here is the link to the post:
[GSM/CDMA] RAZR Utility - xda-developers