To edit an existing document, you first have to open it.
After the document is loaded, you can continue to insert columns, symbols, bar lines etc. into an existing staff.
You can copy or delete sections of the document after selecting them.
To locate specific parts in the document, use the Search and Go To commands.
Use the options on the Format menu to change appearance and dimensions of symbols, cells, columns and staffs. Complete the layout of your document by formatting its pages and adding headers or footers.
After making changes to your document you should save it or save it under a different name.