Its Broken :(
It says Finder cannot open this app
A Remastered Version Of Baldi's Fun New School! · By
Alright, try doing these steps below. (Credit to MichaelDoesGaming for making the unmodified version of this tutorial)
1. First, right click on the BFNS Remastered application, then press “Show Package Contents” and then press on “MacOS”.
2. Once you have done that, open up another finder window, just right click on Finder and press “New Finder Window” then press Applications, and scroll down until you see “Utilities” then scroll down until you find “Terminal”.
3. Then open Terminal and type in: chmod (space) +x (space) and then drag in the BFNS Remastered application. Then press the enter button on terminal. Now go to your downloads and open up the BFNS Remastered application. Now open the application normally.
4. You will see a error screen saying that “filename” can’t be opened because it’s an unidentified developer. Just press the ok button and go to your system preferences, then go to security and privacy, Then you should see “filename” can’t be opened because it’s an unidentified developer. You will see a button saying “Open Anyway” just press it.
5. Then you will see a error sign, just press Open. And there you have it, the mod should now be playable. If this still doesn't make it work, it might be another problem.