Myself, I'd resign if. Copy the signature, lay it over to area needed, press hard with a pen and it should leave an impression to trace
Might want to try a few practice runs until you feel comfortable with doing the real deal. Also may try 2 sheets of paper
Forging signatures to create fraudulent documents is OK with you?
I don't consider that forging if what the OP stated is fact. I'd consider it correcting an honest mistake that can create a hornet's nest if done any other way.
As the others have mentioned, I to have been told by more than one DMV personnel to just step outside and sign on the correct line.
I went through a fiasco in Ca. MANY years ago that was extremely frustrating and had me running on temporary tags for over 3 years due to the same exact reason. The car was then taken by a disgruntled b-t-h I had known. I knew where it was but couldn't retrieve it nor would the local police get involved as it wasn't legally in my name. Call it what you want but I got the pink slip (title) in my name and retrieved the car.
BTW this was the short version of the story