1. register the CD in the package manager. (The package manager works using "repositories", and you want the CD listed as a repository).
2. ctrl-alt-F1 does not kill the X server--it just switched you to a different terminal. You can go back to the GUI with ctrl-alt-F7 (or possibly F8 or F9---on my machine, the first user to log into the GUI gets F7, the 2nd gets F8, etc. I'm not sure if all distros are the same.
Note that you can also get a terminal within the GUI.