I am brand new to Ubuntu Server (or even having a server). I installed Ubuntu Server, installed a GUI using
sudo apt-get install ubuntu-desktop so that I can check for other software graphically.
After finding what I needed I wanted to boot to tty (command line) each time. I have seen it mentioned to change a parameter to "text" but my grub file is "read only" and I wasn't sure how to gain root to edit that file. I then typed
sudo apt-get remove lightdm and seemed to have made a mistake.
The machine now shows Ubuntu and the loading circles but does nothing.
What have I done, and how do I get back to command line boot, with GUI option?