Balloon pmt 4 months head. What can owner do? (sacramento)

[Nguyen Quach]

My friend, who is current owner, has about 260k balloon pmt in 4 month ahead. This is a seller financing. Property is a duplex in South Sacramento, fruitridge and power inn area, and mkt value between 310k-350k. Owner wants to keep it. Owner hasn't credit score, no any asset, the only thing he has is cash income (non verified). And he can pay monthly debt up to 2k. 

Does he has any option/ method to keep the property and solve the balloon pmt?

is it wise to keep the property or sell it?

Thankyou