Change key signature only

[george ports 33]

Am using Win 10 and have Finale 25.5.
I did a song in the key of Bb which should have been in Eb. How can i simply change the key signature to Eb without changing anything else? I read the help section but had trouble understanding it. Am afraid of having to redo everything.
Any help wouild sure be appreciated.
George Ports

[miker]

Make a copy of your score. Then you won’t lose anything.

With the Selection tool, select the entire piece. Right click. From the drop-down menu, choose Edit Key Signature. In the following box, you can change the key and hold the notes to their same staff lines.

[Peter Thomsen]

… I did a song in the key of Bb which should have been in Eb. How can i simply change the key signature to Eb without changing anything else? …

If I understand you correctly, the notation shows the key signature of Bb Major, right?
Bb Major has A natural, while Eb Major has A flat.
Since the music sounds as Eb Major, you have some Ab notes notated with note accidentals, right?

… you can change the key and hold the notes to their same staff lines …

Choosing the option Hold Notes to Same Staff Lines (Modally) will change the Ab notes to Abb notes.

Instead, choose Hold Notes to Original Pitches Chromatically.

[miker]

Thanks for that, Peter.

[george ports 33]

Thanks to Miker and Peter. It all worked and you saved me a lot of time. I really appreciate your help.
Thanks again,
George