Home still not sold 3 1/2 years after divorce. What to do?

The diverce order says that I have to pay 1/2 the mortgage until the house sells. The X is still living in the house for now 3 1/2 years. With housing prices falling fast and they refuse to reduce the selling price on the house to make it sellable. The "X" is very un-motivated to do anything because they are living in the home for basically 1/2 price.

Is there any suggestions or legal advise available to force them to reduce the price or refinance and take it over completely.

Also, The mortage amount still owed is somewhat higher that the current value because of the bad housing market going on now.

House For Sale By Owner