You can't change the treble clef to an octave treble (tenor voice) clef? According to the manual, you can. Once you change the clef, you have to adjust the octave but it's easy.

https://usermanuals.finalemusic.com/PrintMusic2011Mac/PrintMusic.htm

I don't have PrintMusic but it looks little different from Finale in that regard. I use 2-staves for 4 and 5 part male voices if the arrangements are simple,

If you're looking for the movable C clef to substitute as a tenor clef, you need the full version of Finale for that. I know that some Barbershop arrangers still use that affectation.

I have already changed the CLEF from a standard treble clef to an OCTAVE TREBLE CLEF. That's not the problem. The problem is to get the staff (the lines where the notes are placed) to be in piano-style appearance (treble clef on the top and bass clef on the bottom), as opposed to staving four separate voices. After a few hours of trying, I finally opted to moved the name of the instrument staff (PIANO) to a place off the page and entering a "text box" listing the four separate voices. I still think there has got to be a way to get a piano-style staving (treble clef and bass clef) but be able to list the four separate voices. The guys get confused if they see four separate staff/voice lines. Thanks. Sandy

Focus on the desired results, not on how you think it ought to work. Don't use a piano staff.

Instead, create a stave that connects two staffs. Finale has many options for connecting them using Add Bracket.

https://usermanuals.finalemusic.com/PrintMusic2011Mac/PrintMusic.htm

The manual is your friend. Unfortunately, it won't let me link to the two pages that I read describing exactly how to do this but it's all in there.

OK, I couldn't link you to the page but this is the one that you want. You can also use the Setup Wizard to create one from scratch. If you do this often like I, create a template—I probably did mine in Finale 98 or something even older.