Here's my opinion.
1. Use income (that you have accumulated) to repay the debt in whole
The income is consumed by the debt burden. If it was that easy they already would have done it. they are digging holes to cover other ones, waiting for better times, that are away for a (too) long time. I guess they could impose income taxes, - in a way fair to those who enjoyed the benefits of Dubai- but the effect could be devastating on the long term and will never be enough, just have a look to the debt/inhabitant ratio.
2. Refinance all or part of the debt
They'll have a hard time refinancing a debt if they don't have the money to pay the interest of the current debt. Conditions for a new loan will never be as good as they were, the problem will just become bigger.
3. Sell asets, either the security for the debt, or other assets to repay the debt in whole
In Dubai, there are no assets. It is a Brit/Arab dream. A paradise in the desert with no purpose. Empty buildings will stay empty. Its value is simply unknown. What is the value of a Boris Becker tower? Foreign assets are likely to be sold when defaulting, although a lot of this will depend on legislation. To what extent is the owner in Dubai liable? If lost money can't be recovered by selling assets, confidence of investors will drop further/ become 0.
4. Default on the debt (and let bankruptcy run it's course- which will naturally involve asset sales).
Then they won't be able to refinance. Nobody, no bank, is ever going to borrow a Dubai owned company a EUR,USD,RMB again if DPW/Nakheel defaults. Unless there is a written bank guarantee from Abu Dhabi or etc.... A short term resolution that will hurt in the near future. Abu Dhabi cannot be counted on. Western investors will demand guarantees for future loans that can't be given.
What -imho- they should do is confess and communicate, contain the situation by making very clear what is available, icw transparent books. I don't think they will be able to provide enough clarity to calm down the markets. If people start dumping Dirhams on monday for EUR/USD/etc it may make things worse. Possibly only EK has transparent bookkeeping for dealing with foreign agencies regarding fair competition. Unfortunately it has the same owner as Nakheel who couldn't / doesn't want to pay its upcoming commitment for Nakheel. Would anyone here borrow mony to a company with a unreliable owner?