Kaiser Lock & Key

-The first best option would be to contact the cabinet manufacturer and see if they are able to send a replacement key, or if they have specific instructions for unlocked the filing cabinet without using special tools.

-If the manufacturer is unavailable or is unable to assist, then the lock will generally need to be picked or drilled out, which is best left to a professional locksmith and it is not recommended that you attempt these yourself as causing damage to the lock may make it harder and subsequently more expensive for a locksmith to perform the necessary service.