Noteman says: View the Resize my staff, system, or page QuickStart Video for an overview.
This tool lets you reduce or enlarge a note, group of notes, staff, system, page, or all the music in a piece. When you use it at the note-by-note level, you can create cue notes; at the staff level, you can create a cue staff. However, you’ll probably use this tool most often to reduce the overall size of the music. It’s important that you choose Utilities > Update Layout after you reduce or enlarge a system, a page, or the entire piece so that Finale corrects any irregularities in measure widths introduced by the change. See Reducing/Enlarging.