Yea sorry for being brief. Using the ctrl, alt, F1 keys this will bring you the command line and log in. Then
Before you run the nvidia file you will need to cd change directory to where you downloaded the file. If it is on your desktop the then run the sh nvidia driver.
sudo /etc/init.d/gdm stop
make sure it is your name of file.
sudo sh NVIDIA-Linux-x86_64-185.19-pkg2.run
To get back to the desktop you can just change the stop part of the command to start.
Also you may see a error to install build-essential first.
New thread here