Disable or enable rootless for Mac os X 10.11.6 El Capitan, step by step

{ check rootless status}

csrutil status
//System Integrity Protection status: disabled.
//System Integrity Protection status: enabled.

{ close rootless }

1. restart system and hold option
2. select "recovery" in disk select screen
3. top menu bar select Utility -> Terminal
4. input :csrutil disable //disable rootless
5. input: reboot //reboot system

{ open rootless }

1. restart system and hold option
2. select "recovery" in disk select screen
3. top menu bar select Utility -> Terminal
4. input :csrutil enable //enable rootless
5. input: reboot //reboot system