My grandmother is the lender for a home.We would like the borrowers to refinance or can we sell the mortgage?

My aunt abused her POA for Grandma and sold one of her properties (we have been to a lawyer who states the sale was legal). My aunt used Grandma as the or the mortgage company per se. Grandma does not want to be the lender. She is 87 years old and this is a 30 year note for $80K with 2%, yes that's TWO percent interest. We would like to know how to make the borrowers refinance the loan elsewhere... that to ask them to refinance? Please HELP! Yes, you would have to use that to ask them to refinance