how enter the command enviroment in GUI
 

in order to install the NVIDIA driver , you must in a fully command enviroment,
but how enter into that command enveroment from KDE quickly without reboot you computer.

regards!

Print out the instructions or put it in a text file so that you can view them when you exit the GUI
Press ctrl-alt F1 (or F2 or F3 ... up to F6)
Log in as the root user
Type:
init 3
That's it. Follow the rest of the instructions...