You need to take the Lien release and a POA from whoevers name the title is in (or get them to take it) to your local DMV or down to the Main DMV in Hapeville. Once the new title is printed in the previous owners name, then you can then transfer the title into your name.

What year is the car? If its older than 1986 then you can use a BIll of Sale to transfer ownership-- but anything newer and you have to use a title.