I have some Mac OS Xs around me (Intel and PPC ones as well), and usually I find the opportunity to create a nice kernel panic :] But I always forget how to list the already loaded kernel extensions:
kextstat
To load a kernel extension, type:
kextload /System/Library/SomeCool.kext
to unload a kext, type:
kextunload /System/Library/SomeCool.kext
If you want to replace any kexts, just simply copy over as root (i usually do it in midnight commander) and after say:
chmod -R 755 /System/Library/Extensions/SomeCool.kext
chown -R root:wheel /System/Library/Extensions/SomeCool.kext
and clear the kernel cache:
kextcache -k /System/Library/Extensions/
BTW this commands will not work - kext is not ordinary file, it is a bundle. So you need to set permissions not to kext itself, but also to files inside it.
The most simple way to do this is just run Disk Utility and make “Repair permissions” on your boot volume.
Of course it is not working. Please RTFM for what -R means, dude.