Do you mean to remove the sheets, or the multiple windows? If it is the
multiple windows you want to get rid of, then select the window that
says filename:2 and click the close icon for the file window (NOT the
Excel close icon). Keep doing this for filename:3, filename:4 etc until
you only have one left, which should have just filename in the title
bar.
Alternatively, you could click Window and you will see the windows that
are open - deselect the windows you do not want.
Whichever way you do this, you should then save the file.
Hope this helps.
Pete