How to remove XFCE login screen and Revert to Unity login?

[Kpenguin]

Hi everyone,
I recently installed the XFCE desktop environment alongside unity and KDE on my laptop. I liked the Unity login screen better than the XFCE login screen and I'm trying to figure out how to revert. It's also causing problems when I lock the screen during a Ubuntu Unity session. I found another thread on this forum about this, but I got some error when I got to the second command. Help please?
Thanks,
Kpenguin

[Kpenguin]

I fixed the login screen problem by editing some config file, but I'd like to change the unity login screen background and get the grid lines back. How do I do that?