How to unlock MAC EFI Icloud with 6 digit PIN Lock passcode
Macbook Pro -- iMac
1) Add or remove a stick of ram. Obviously if you have one stick in, add one and if you have two in remove one.
2) Power on the mac and immediately press and hold command-option-P-R. ( only 1 chance, if failed need to remove / add ram before next attempt )
3) The system will restart with the 'bong noise', allow it to do this 3 times. On the third 'bong' you can let go of the keys.
The machine will now boot with a cleared password and reset PRAM/NVRAM.
You can shut down the machine and replace the original ram configuration.
After unlock you will need to wipe the hard drive totally ( Need to boot from DVD or USB install disk)
Find your RAM
MacbookPro : Flip mac upside down, remove all screws on back cover, once remove it should be visible.
iMac: Turn iMac upside down, under the screen there is a small grill with 3 screws, removed them and RAM should be visible.
For Mac PC made after mid2010 this free method will not work.
Check your MAC with your serial number at apple:
There are a few options to unlock:
1) For Any User: EFI buteforce device with LCD
2) For user with basic computer skill: Remote unlock service ( access to another MAC and a usb memory stick require )
3) For Techincal user: Bios Chip programmer tool kit (with 1 x blank bios chip supplied)