Without the other owner of the vehicle signing the form there is nothing that DMV can do. Going into a office will just be a waste of your time. If the co-owner is refusing to sign the title it then becomes a civil matter.
If this was part of the divorce take whatever documentation you have for proof to a local DMV office. Worse case they can give you the paperwork you need, you fill it out and then have the ex spouse just sign.
Thanks! Your answer is awaiting moderation.