Changing the clef of where a note is scored

I am scoring a piano piece. The top note of the arpeggio being played by the left hand is appearing in the treble clef. How do I change the clef of this note to appear in the bass clef without changing the split note?

Right click on the highest note: Display in Staff>(staff name - Lower).
Then remove the flag beam for that note in the Set Note Info dialog (select note, hit i in the toolbar (or double click on the note head), and check “No Flag Beam”)

Alternatively instead of using Split to specify which notes go to which Staff use the Polyphonic setting. Then the Staff used for a specific Note is determined by the MIDI Channel Number of the Note not its Pitch.

I should’ve added that I’m using an iMac OS Catalina, so I can’t ‘right click’ The Maestro.

Thanks Rain, using ‘piano polyphonic’ instead of ‘piano split’ did the trick.
Thanks so much both of you for responding to my plea.

Of course, but you loose the split functionality.
You decide.

If I am not mistaken, you can enable right-click in the system preferences on your Mac.

If you want to right-click, hold CTRL (control key), then click.