You don't. Ask yourself, would you pay more for something then it is worth? We both know the answer to that question. Even if you found a buyer who was uninformed, they will never get the financing.
The best way to structure this sale would be to offer to sell with a very low downpayment with you holding the mortgage. This could be risky if you don't do your homework and make sure that the buyer is a solid citizen with good credit. There are some good, credit worthy buyers, who may have a good job but have not work at it long enough to be able to save enough for a downpayment. This is who you should be looking for. It may also mean that you may have to rent instead of buying.
Look at the math. If the value of your house is now $250,000 (you didn't indicate the value) and a buyer could put up $10,000 and has a few thousand for closing costs, at 6% interest you would collect $1,438.92 a month on a 30 year payout. With a 5 year ballon (hopefully things will be much better by then!) the buyer will need to refinance and pay you about $223,330. Add that to the $10,000 downpayment and $86,335 that you have received in monthly payments and it comes to $319,665. You could also work the numbers for a 3 year ballon and see how that looks.