You can try:
login (to login)
then to start X by typing: startx

If x fails to start and you are in the terminal, you can try:sudo
dpkg-reconfigure xserver-xorg
Failing this you can try to reinstall kubuntu from apt as follows:
sudo apt-get install kubuntu-desktop

This should get you back to where you were before you began to remove kubuntu.

I am wondering why you were removing Kubuntu. Do you have another desktop
installed? If you do, then you should be able to avoid reinstalling Kubuntu and
startx after you reconfigure xserver-xorg.