How do you refinance a loan from a family member into a mortgage?

[Ellie Narie]

Let's say that you want to buy land and build a fourplex, however, you are newly self employed, and you won't qualify for mortgage loans for another 2 years, since banks need a 2 year tax return history. 

However, a friend or a distant family member is willing to loan you the money for this. But, they don't want to set up a whole 30 year mortgage for you, they want their money back in 2-3 years. The relative would give cash as a loan to buy the land and build, and then 2 years later, you'd need to take out a real mortgage from the bank and pay back the relative. How would you recommend going about this process?