Creative purchasing owner financed home

[Demetrius Dillon]

How to draw up a agreement for a purchase leaving current mortgage in place. Owner only asking for current monthly payments and seller to cover all home expenses for the remaining duration of loan. Protection for both parties in the unfortunate act of lost of life. Also best approach to showing the current mortgage company that leaving policy in place would be better for all parties. Seller is self employed and has faced some funding hurdles in the past.