you do have pkgtools installed dont you?You can check in /var/log/packages
check /etc/fstab and see where the cdrom gets mounted, cd into that directory
you have to be root to do most of this---including package tools, no changes to the system can be done by a regular user
I have no clue why you are having so many problems with this, more info would help I guess
if all else fails, reinstall but dont select reformat the linux partition, just install over it, it wont kill whats already there--------realy not the way to go, thats the typical windows solution, reformat everytime something goes wrong, linux you just fix it and move on