MacBookPro 2011 GPU failure. Csrutil command will not work at all I am having the GPU failure issue and I'm trying to disable some kexts however i'm constantly told operation permitted. 

I am following Lizardtrons video on Youtube where it seems atleast 2.2K people have had success however I'm stuck. 

https://youtu.be/nFFPk3SeQbQ

I have installed Dosdudes software to automatically delete the kexts for me however it still says SIP is enabled.

I am running MacOS Sierra 10.12.6. I can add more info if needed.

I cannot for the life of me disable csrutil in terminal, safe mode or recovery mode. It says the command is not found. It is as if computer does not know the command.

However when I type in 'csrutil status' in terminal on the desktop it actually says SIP enabled. 

So its recognising it on the desktop terminal but not on safe mode(cmd S) and Recovery mode (cmd R). 

I have also tried internet recovery to newest install newest OS however it only promts me to install OX Lion.

I installed El Capitan onto an external HD to see if I could boot a new OS from that but when holding option key prior to boot, the only HD that comes up is the internal drive and not the external boot drive.

I am running MacOS Sierra 10.12.6

All i need to do is 'csrutil disable' so operations can be permitted. 

I've been at it for 3 days now and I really don't want to give up as I've got a week off work and decided to dig this out of its death!

Any help is greatly appricieated. I am not 100% tech savy however I can adapt fast with instructions etc

Also sorry if the question is all over the place.
Just incase anyone had this same issue.

I had to use a new external HD (backed up everything onto it) and booted with that using option button.

Then erased the internal disk using disk utility and it then allowed me to do a fresh MacOS which then updated the recover software to 10.12.6 Sierra. 

Which then therefore allowed me to disable csrutil in Recovery mode.