Hi, 
i am doing the guide, first thank you very much... 
I am from spain, so sorry for my english... 
I did the install...and have the ml 6.8.5...working but with some problems.... 
  
i could not use de kext wizard in Post-Installation: 
  
step 11,12 Select System/Library/Extensions under Destination...(you say this but in the photo are marked  "Extra"... 
step 19: Check the boxes next to "Extra" and "System/Library/Extensions" 
  
my problem is that i can not check Extra...if choose my ML hard drive i can not choose this option....i only can choose "extra" in  myHack OS X Install Disk. 
  
So i tried with kext drop some drivers like audio now work, but i can not start from the hdd drive...i have to reboot always from USB...so what can i do?...what i am doing bad?... 
if i try from hdd-drive, just show me the apple with the infinite circle spin, and a prohibited simbol at the end... 
  
The wifi doesnt work too, i tried with the airportd.zip , but i can not use it... 
  
i have a e6410, i5, nvidia v3 graphics, 8 Gb ram,  
  
Best Regards Fernando