The second option is unplugging all accessories attached to your Mac including external hard drives and printer. The last step is restarting your Mac in recovery mode.

To do that, first restart your Mac in Recovery mode, open the Utilities menu and run Terminal. From there, type csrutil disable and hit Enter, then restart your Mac.

I’ve put together an essential foundation document for Mac users who may sometimes try to help support friends and family. Still having problems? Restart the Mac holding down Command-R to enter ...

Ordinarily, the only way to disable SIP is to restart your Mac in Recovery mode, enter a specific command into the Terminal, then restart again.