easiest way to get $ back at closing from seller

[Dain Hungelmann]

I'm buying a multi  unit in Milwaukee for 85k  Valued at 110k.  Seller is willing to give back the 25k at closing ( my 20% down) but I'm trying to figure out the best/legal way to do it.  Lender will allow it for a 7-9% rate. Don't want to do that then refi for a better rate . I've been told i can do it if there's a second mortgage in place. So I was thinking about having them signing a second mortgage , non recorded, and he can pay it at closing.  Can I put it in my name or do i have to put in someone else's name?