Ha ha hahahah hahahhahah <slap>

Sorry
I didn't say a word. I typed all this instead..
nVidia Driver Installation NHF
nVidia driver page
Download the script, then open an x terminal and give these commands:
su -
<answer prompt with root's password>
chmod 755 /path/to/<filename>.sh
/path/to/<filename>.sh
Watch out for capital letters. Linux is case sensitive and iirc, it's named NVchoser.sh or NVChoser.sh
What these strange commands do:
chmod 755 - Make a file executable (sets the executable flag for owner,group,others)
/path/to/<filename>.sh
or
./<filename>.sh (when you are in the directory with the script)
Executes the file.