XSpreadsheets sheets = document.getSheets();
// delete all sheets except one
String[] sheetNames = sheets.getElementNames();
for ( short i = 1; i < sheetNames.length; ++i )
sheets.removeByName( sheetNames[ i ] );
// need 5 sheets
String[] newSheetNames = new String[] { "first", "second", "third", "forth", "fifth" };
// give the first one the right name