Disable dual Graphic and use only Intel card My Mac Book Pro is now stuck after Apple logo screen on a grey screen and after hours of search I found the problem is in my graphic card (this issue happen after updating to High Sierra).

So  I need to disable the second VGA 

I tried with

/sbin/fsck -fy /
/sbin/mount -uw /
mkdir /Disabled_System_Library_Extensions
cd /Disabled_System_Library_Extensions
mv /System/Library/Extensions/ATI* .
mv /System/Library/Extensions/AMD* .
touch /System/Library/Extensions
exit


but I got an error : 

operation not permitted


any idea to fix this or at least disable SIP ?

Notes  

I am not able to boot to any GUI neither by safe mode boot nor verbose mode or even recovery mode,  so I need to do it via terminal  

I am only able to boot via single user mode
The only way to disable SIP is to go in through the recovery partition and disable it from there, so unfortunately I don't think that will be an option for you with the current state of the machine.

I would take a look at the answer for this question here:
MacBook Pro How To Disable Discrete GPU Permanently from EFI

Booting into a different OS is probably going to be your best chance at success. Hope that helps!