How to rebuild kext cache on Mountain Lion 10.8

kext cache rebuild is just a two-step task.

1. sudo touch /System/Library/Extensions/
2. sudo reboot

It's NOT recommended to execute kextcache manually.

KEXTCACHE(8)              BSD System Manager's Manual             KEXTCACHE(8)

Caution: Incorrect use of kextcache can render a volume incapable of startup.  Installers and administrators should not use this program to

     update system kext caches.  Instead they should run touch(1) on the /System/Library/Extensions/ directory of the installation target volume

     after they have finished, which invalidates the existing caches and causes the system to update all necessary kext caches.