code: private void updateDefault(final Instance _inst,
                                 final String _value)
      {
          try {
              final Update update = new Update(_inst);
              update.add("Default", _value);
              update.execute();
          } catch (final EFapsException e) {
              DBPropertiesUpdate.LOG.error("updateDefault(String, String)", e);
          }
      }
docs: Update a Default.
  
  @param _inst      OID of the value to update
  @param _value    value