What is the legal way to buying and holding owner financed property with a mortgage

[Bob Olah]

Hello Guys,
I have read so much from soooo many investors that I really want it clearified here please.
If I find a motivated seller who just wants out of a property, Can I buy it legally with owner financing? I do not want to use lease options ( I do not want to flip it, plus what if something happens to the owner of the property)? I like the idea of getting the deed and owning without all those conventional banking fees and expenses.
But what is confusing me is the due on sale clause? Some people say you can do it and go around it hoping the bank does not call the loan due. Some people say no don't do it, its sneaky and your hiding it putting it in a land trust because you never record it.
Can I have some input on what is the correct way to buy and hold (while getting the deed) to a owner financed property with a existing loan?
Seems like quite a few people here have taken over existing mortgages .....
Subject to, land trusts, etc.... Last question, do you use a lawyer for the final closing or contract assignment?
If this is too much you can email me. Bob
Thanks for all the info......