[Modena]

To answer your specific question, the FASTEST and CHEAPEST way, short term, to transfer it to your name is to cancel the registration (you will get a refund from Vic Roads on the term remaining when you do this) and then perform a clear title transfer of the vehicle to your name - this is just a letter signed by both parties that your old man is giving it to you, ensure that this document is certified/witnessed by a copper, pharmacist, JP or similar.

Then you can re-engine/roadworthy/re-register at your leisure. When you come to do this you will need the dated certified witnessed letter to prove to VicRoads that is does it fact belong to you and not to your old man.

This might sound like a lot of trouble, but it's actually just a letter you write (two sentences!) and a visit to your friendly VicPol station and VicRoads, and your old man will be free of it instantly. Don't forget to change insurance details/names also or that might go against you - just tidy up the lose ends.