Apple: Bypass Mac Firmware Password

This solution should work on both EFI (Intel) and OFI (PPC) based Macs. This is a hardware based hack, proceed with caution! We are not responsible for anything that may go wrong in the process.

Essentially you are removing the systems RAM and reinstalling it, here are the steps for a MacBook. This works the same on other Macs, but removing the RAM is obviously different, so you’d need to understand how to do that. Here are instructions for MacBooks:

1. Shut down your computer
2. Remove the battery
3. Remove the three philips head screws that are on the L-bracket
4. Remove the L-bracket
5. Slide one of the levers (it doesnt matter which one) to the left. This will release the RAM
6. Gently wiggle the RAM card out and put it aside, you will put it back later(do NOT touch the gold bars on the front; you could break it)
7. Replace the L-bracket and put the battery back in
8. Boot up the computer while holding COMMAND+OPTION+P+R (this resets the parameter ram)
9. Wait for the startup chime to sound 3 times
10. Release the keys and shutdown the machine once you reach the login screen
11. Remove Battery and L-Bracket, replace the RAM module and slide the lever back while pushing it in until it does not wiggle anymore
12. Replace The battery and L-Bracket
13. Now if you boot up the machine you should bypass the Mac firmware password

You can now use the machine as usual, boot from an external drive, or whatever else.