Changing the icon when turning your game into a single executable file

[MichaelNG789]

I am doing this for Mac, and I have made my custom icon as a .icns file. When I replace the .icns file in the app with my custom icon, it doesn't work. (note the .icns file is still called Solarus.icns, which was the same as the one the app came with) Did I go wrong somewhere? Is there a possibility that I had to edit info.plist for it to work or something? The other games by the Solarus team have the same thing and their custom icon works fine.

EDIT: Also the weirdest thing is when I move the app to trash the .icns file works, but when I put the app back it doesn't work again.