For managing the Mac OS X firmware password, you can use the Open Firmware Password application. This works with Mac OS X 10.1 and later. For further details regarding managing Mac OSX firmware protection, read Apple’s online documentation.
There are several easy steps to disable the mac’s firmware password:
1. Launch the Open Firmware Password application
2. Click the icon ( authentication ) and provide your admin login details (includes the admin password)
3. Click on the change button
4. An Open Firmware Password window will appear on your screen.
5. Un-check (deselect) the “Require password to change Open Firmware settings” option from that window
6. Click “OK” to submit your changes
7. Select the lock icon again and you are all set