Editing the /System/Library/LaunchDaemons/com.apple.pfctl.plist file I need to vim the file found at /System/Library/LaunchDaemons/com.apple.pfctl.plist but the permissions will not allow it. Even when I run sudo vim /System/Library/LaunchDaemons/com.apple.pfctl.plist and enter my password, VIM throws me a warning and says that I'm editing a readonly file. Any ideas how to do this?

I'm running OS X 10.11 El Capitain.
Some paths and applications in El Capitan are protected by System Integrity Protection. Even root can't modify the files. You first have to disable SIP before editing or modifying them.


Reboot your Mac to Recovery Mode by restarting your computer and holding down CommandR until the Apple logo appears on your screen.
Click Utilities -> Terminal.
In the Terminal window, enter in csrutil disable and press Enter.
Restart your Mac
Modify the file(s)
Reboot your Mac to Recovery Mode by restarting your computer and holding down CommandR until the Apple logo appears on your screen.
Click Utilities -> Terminal.
In the Terminal window, enter in csrutil enable and press Enter.
Restart your Mac