For example, try to move the Chess app to the trash and you’ll see a message saying, “Chess can’t be modified or deleted because it’s required by OS X.” How to Remove Left Behind Files Note that you can’t remove built-in applications by doing this. Uninstalling them will remove whatever system-wide changes they made. These applications were installed using the Mac package installer.

However, some applications will prompt you for a password when you try to move them to the trash.