How will disable selinux from redhat linux?

Go through below steps :

Edit below SELINUX file to disable / enable

#vi /etc/sysconfig/selinux

append / edit with below configuration (for disabling)

SELINUX=disabled

Now, You will have to go for the reboot once to apply the above configuration changes

#reboot

Step -1 : vi /etc/sysconfig/selinux  

Step -2 : SELINUX=disabled

Step -3: reboot

 vi /etc/selinux/config

then change the value to disable and save the file and restart your server with

shutdown now