how can one bring down a HDD password?

If the computer is owned by you and it has a BIOS password, you can open the computer's case and look for either the jumper to reset the BIOS, or if it has a battery, remove it, leave it out for a few seconds, and put it back in. That will reset the BIOS back to defaults and remove any password.

With regard to a password on the HDD...

If the hard drive is encrypted and you need a password to access it, and you dont have it, you are out of luck.

Why is your question title 'Man'?