How do bankrupt countries get rid of their debt?

Just default on it because you determine the debt to be "immoral".
Calling Foreign Debt 'Immoral,' Leader Allows Ecuador to Default
It is exceedingly rare in global finance for a nation not to honor its debt because it doesn't want to, as opposed to not being able to make payments because of a financial crunch. Some analysts fear it may set a precedent, emboldening other leaders who share Correa's ideology -- such as Venezuela's Hugo Chávez -- to make similar pronouncements.