Best way to take title on this real estate transaction

[Dee Xixi]

I have a burn out landlord that want to sell a 7 units in my area. lRight before the market crash he put up some serious money into the building for a complete rehab. He wants to sell the property for a reasonable price which will still cash flow positively and cap rate at 9% for the area is not an awesome deal by no mean.
I offer to take the property with existing financing but I am wandering what is the best way to transfer to an llc or trust and at the end i can refi instead than purchase?

Please help out.