How to transpose and get it right

Right-click on the staff, choose "Staff Properties…", click the "Change Instrument…" button on the right, and there you go.

Just create a blank piano score then copy your piano piece to it. Once you're done, right-click and choose Stave Properties and change the instrument to a sax. Another way would be to ADD a tenor sax to the score and then you can Copy (select a range of notes and [Ctrl]c) notes from the piano piece and Paste ([Ctrl]v) to the sax stave and they get transposed for you. That way you can make alterations to the sax piece but still see the piano piece.

Or, when you first create the music, set it up for soprano sax but press the Concert Pitch button to turn that on before entering notes. Now you can enter notes at concert pitch, then when you are done, press Concert Pitch again to turn that off, and the notes will autoamtically be transposed.