[macos] Operation Not Permitted when on root - El Capitan (rootless disabled)

If you want to take control of /usr/bin/

You will need to reboot your system:

Right after the boot sound, Hold down Command-R to boot into the Recovery System

Click the Utilities menu and select Terminal

Type csrutil disable and press return

Click the ? menu and select Restart

Once you have committed your changes, make sure to re-enable SIP! It does a lot to protect your system. (Same steps as above except type: csrutil enable)