Disable SIP without recovery mode
Edit: to answer your actual question, you can't do it from anywhere except Recovery Mode, so anything you do must be done from there.

Tested on a similar 4,1 upgraded to 5,1 [but I have a flashed graphics card so I could see what I was doing]

Reboot &amp; at the chimes hold  Cmd ⌘   R  for about 10s.
Wait until you get to Recovery Mode, which for me took approx 45s from the chimes [I'm on SSD but I think it may have chosen a Recovery on another HD to actually boot from] Give it a minute or so just to be safe.

 Fn   Ctrl ⌃   F2  will switch focus to the menu bar, specifically the Apple logo, top left.   

It appears that whatever you have set in System Prefs > Keyboard for "Use all F1, F2 keys as standard function keys" that this option is disabled in Recovery, so even though just  Ctrl ⌃   F2  works for me in a running OS, in Recovery I needed the added  Fn  key.

From there, you can navigate using the arrow keys 

Pic from https://apple.stackexchange.com/a/254167/85275

 

From that you can see that Terminal is 4 to the right, then 4 down.
It's 4 not 3 because the first down arrow opens the menu.

Hit Enter &amp; Terminal will launch.
Type csrutil disable &amp; hit Enter
Type reboot &amp; hit Enter.

If it reboots, you got it right - otherwise you'll have to have another guess.

BTW, golden rule, as you have discovered, is keep your crappy old stock Apple card somewhere safe, for occasions such as this ;-)

Additional note:  Fn   Ctrl ⌃   F2  is a toggle. First will select the menu bar, second will deselect, so make sure to only do it once.