Use the tools listed above. Overwriting sectors with zeros or random data works perfectly. hdd wipe tool download
DBAN is the gold standard for bulk HDD wiping. It is a self-contained boot image that you "burn" to a USB drive. Use the tools listed above
Stay plugged into power and let the process finish. Large drives can take several hours to complete a deep wipe. hdd wipe tool download
Traditional "wiping" doesn't work the same way due to "wear leveling." For SSDs, you should use the Secure Erase command found in the manufacturer's software (like Samsung Magician or Crucial Storage Executive). How to Safely Wipe Your Drive